None of the above.
"End game" being part of design concept is wrong. It has to be removed out of players/developers minds. And many others concepts with such words as "power creep" or "class" or "levels", which only create problems to those who dont know what they are designing.
Design intending for an end is wrong, focusing on an end is foolishness. "Speed running" or "fast eating", all foolishness altogether.
You can have a little berry at the top of the cake, where the little berry is representative of the "end". Any more significance to the little berry, compared to the cake itself (99%+) is simply put: wrong. Longevity is key, below 10 thousand hours expectation and your not a true passionate hardcore game as art designer.
Get out of the game design field if you disagree. Therefore I said none of those. I will explain better, but for that I will have to give examples of many games in different genres.
An approach hybridized (a cross between only the best fractionized aspect of each) and evolved from:
similar to true old school MMORPGs (over 51% of the content has to be non combat: but professions/tradeskills, but for Christ sake no more medieval themed, but sci-fi futuristic metaphysical [your mature pedagogic spiritual, instead of simply magic, fantasy equivalent]), free form open world single player games where the focus is not the end; examples: games from X-Series,
Minecraft, Terraria and Starbound.
or the games designed with foundations and structures of simulation of a virtual world/galaxies that is organic, living, breathing, fauna, flora, interactions, etc. Such as Dwarf Fortress, Rimworld, likes.
Recently we reached the age of "procedurally generation". Which not properly explained, cannot be perceived.
You want a system always online, massive in all aspects with multiple players and artificial ai disguised/non disguised, think Space Rangers HD heroes simulating competition/cooperation with the player, rolling procedurally random generated or consequential/causal events that sprawl more branching events, as one that watches the news in many online newspapers worldwide never runs out of, or as God designed different cyclic systems for nature, animals, weather, humans, etc. Not everyone can complete the same events at the same time, etc. Keep the rule of "if everyone player is a hero noone is", instead of the fake/secret rule of "balance win loss ratio to 50% x 50%".
Soldak Interactive games such as Depths of Peril give an idea of a procedural system of events.
Games with the "Nemesis System", the Lord of the Rings and recently the Warframe.
Games such as Mount and Blade, its clones and Battle Brothers.
You want something that feels neverending story, like Star Wars Galaxies, or Saga of Ryzom, or Uncharted Waters Online.
Justice systems similar to Ultima Online, Haven and Hearth, EVE Online but actually taken seriously.
Political systems similar to Shadowbane, but with the mechanical limitations you find on big diverse empires on those 4x or grand strategy games, such as Stellaris and Distant Worlds to prevent a 1000 chinese players community numeric imbalance that you can see of Life is Feudal or other games with free numeric field (absence of field design).
The design of the "playable areas" has to follow Rock Star studios level of proper city building, but even more interaction (and futuristic), gta type playground, so whatever concrete logistics design (traveling) is acceptable and interesting (radios/news/socialization/streaming systems).
Those are some of the light boxes I could think in the few minutes I wrote this that need to be properly assembled together.
Game world virtual reality escape, social, pedagogic, entertainment, spiritual evolution (the place where sins, evil, wickedness, foolishness are TO BE BOUND) and the most wide amount of human factor that can be gathered together to be trained/exercised/tested in a system. Therefore, 6d of freedom for gameplay, strafe to aim accuracy equivalent (left hand to right hand such as in arena shooter Unreal Tournament, or old shooters such as precursors of Star Citizen: Elite and Freelancer online pvp) all camera angles, etc. Combat has to be severely reduced to some 20% of the bulk of content in the game, but high ratio of player to player interactions per minute to keep "true viewership", like cats/dogs interacting with balls.
Something with depth complexity on the skinner box Progression "rpg", with 4-5 stars, like Path of Exiles, Warframe, or old chinese games such as Conquer Online, Eudemons Online (without the whale soul hook of greedy monetization)
It has to have a refresh/shuffle/cycle system like Realm of the Mad God, 24/7 active, instantaneous to get in and get hooked.
Proper risk reward penalties systems, with acceptable consequences to teach players wisdom with ressurrection/reincarnation/inheritance/legacy subsystems, but not of Roguelikes and not of Roguelites, give it a new name that is more proper.
Closest thing to the best game yet to be ever made: with proper field design, balance and progression ratios, volumetric player interaction, viewership attractiveness, longevity, progression, player skill, was a vietnamese game that got forbidden because of all the US war and China punitive war on Vietnam.. It was called Battleswarm or Field of Honor, which I played the Beta and it closed down on the beta, not because it failed or anything, but because the government shut it down due to violence culture law design. A true buried treasure that the big franchises wish they have had a glimpse of. Deep Rock Galactic barely scratch that feel, which is properly found in Starship Troopers, Starcraft, Warhammer 40k universes. It had all the structure check marks that todays popular games (MOBAs, BattleRoyales, Shooters, RPGs) are lacking in one or two aspects, matching rts players vs action shooters, interacting with and against each other. A little bit like Planetside and Helldivers ongoing global wars narrative.
A close second is a game called Ace Online, initially called Space Cowboys. Which also had proper structural design to be popular: viewed and played, for a long time, but of course, what was built on top was what ruined it, things like monetization, localization, server wipes, slow content, etc. But still, the structure of both games mentioned above are the top ones, one for earth, the other for heaven :D
A "Christ" game that we have been waiting for many years have to emulate the best trait of those games in perfect harmony, so that we can have a proper "escapist plataform", until the current human estate systems (both in west and east) are changed to acceptable high spiritual levels of equality, morality, and every aspect, through a true Christ for human earthly systems.
with all that said,
Call my system "Natural" or "emergent" (misused word from Bethesda)
all those awesome hand crafted settings/stories/dialog/immersion will still exist, but within the procedurally events systems... fuck those branching, linear, goal, fake etc options, they are history in my mind already and bothersome to witness.
nothing but a bloodstain in the wall as the Vampire Sabath ruler said on the Bloodlines radio.