That's because leveling in D3 = tutorial. There's no scaling with Paragon and there are twenty difficulty levels so you can adjust monster strength to whatever you want. It just makes you fork out some mats to buy new gear once in a while for the first hour or two of a new season.
It makes 0 sense in D4 and it is arguably the worst part of the game.
Are you actually deluding yourself D4 won't be an "endgame focused" game ? It will just be 90+ or 95+ wherever they trigger the hard xp fallof.
Has it been confirmed, that the game scales infinitely with Paragon levels?
...
So far this seems like fighting a strawman because no one knows if they are so retarded to level scale the endgame overworld in an obnoxious way. Level scaling during leveling can be debated as shit, but it is what it is and is nothing new.
Was confirmed paragons are finite in d4 (0-50 skill points, 50-100 paragon points, + whatever extras). At release at least, though the system is designed with finite points in mind.
Endgame overworld will be scaled. That's the whole point, to have ALL content available at "endgame".
What I meant was that it should (and probably will) be feasible to reasonably outscale the overworld content through synergies, paragons etc. so that generic content will get easier (ergo you feeling more powerful) over time and with character progression.
Bad level scaling like vanilla Oblivion makes you feel weaker with more level ups because opponents become HP sponges while you have limited options to boost your power and your own gain from levels is relatively limited compared to opponents. I don't think this will be the case (and it wasn't the case in Beta and Server Slam, with good gear and skill synergies you were able to roflstomp generic mobs that once posed some challenge despite them being scaled and giving you a hard time during leveling).
Level scaling done right can even be beneficial for a loot grinder aRPG like this, as can be seen in D2R with the introduction of terror zones. In Diablo 2 (no level scaling at all), with higher charlevels fewer and fewer areas are worth farming until from lvl95+ only three mobs even give noticeable XP: Diablo, Baal and maybe Nihlatak.
To minmax XP from these (the only way to move your XP bar forward), you need some convoluted procedures involving a team of ideally 7 other players sitting in the game to provide XP scaling and prepare those bosses for you to last hit (leaving the party before you do). Killing only Diablo and Baal over and over again with a full party that is supporting you and does not interfere with you lasthitting those bosses is the only way to progress (because only these mobs have a high enough level to be worth XP). Coincidentally, the areas of Diablo (Chaos Sanctuary) and Baal (Throne of Destruction) were part of the select few that could drop high end unique items. There were some other areas that could possibly drop those uniques but would't give any noticeable XP at high level, so doing DiaBaal-Runs over and over again was also competing for the best loot strat.
-> There were very limited options besides just doing the same shit all day if you want any progress at all.
D2R introduced terror zones. Every full hour a randomly selected overworld zone is declared a terror zone and mobs in this zone are scaled to your level without limit. This means that they are considerably tougher, give noticeable XP and can drop good loot. I found this to be quite refreshing, because farming the terror zones takes you through different areas in all acts and gives a sense to visiting them and fighting the various mobs with enhanced challenge (and not only Diablo and Baal).
In my opinion, the only "drawback" with these is that you can now reach lvl 99 as a normie who does not have a clan supporting and preparing bosses for you, so high charlevels lose some "elite" status. I personally couldn't care less, as I am certainly not 24/7-ing Diablo and Baal over weeks to move my XP bar at a snail's pace.
Diablo 4 is not a choice and consequence cRPG with hand crafted and carefully balanced combat encounters, it's a hack'n'slash lootgrinder, so level scaling done right could be fine and provide a more diverse experience (as more areas are worth visiting). Roflstomping low level areas in D2 and not having any chance for decent loot or XP gets old really fast. The game just has to give you enough options to get an upper hand over the enemy besides just char level.
Real endgame content is probably OVERscaled anyway (mobs being max. level in e.g. nightmare dungeons)