there's no metric that we can look at objectively here
To specifically address this point: Yes, games can be rated objectively.
You can analyze a game's systemic complexity and how well the systems interact with each other.
You can analyze the flow of level design, the sheer size of a level, and how much content there is to discover in it.
You can analyze a game's story from a storyfag point of view - and yes, storytelling also has objective qualities: pacing, structure, prose quality.
And objectively speaking, many classic games of the past are still unsurpassed in certain aspects.
The stealth systems of Thief are objectively the best: sound propagation, light and darkness mechanics, etc. Its AI is pretty rudimentary from a modern perspective and very easy to trick, but the underlying systems are excellent. No other game even attempts to emulate Thief's light and shadow based stealth, and for some reason no game since managed to have as tight of a sound propagation.
I like RPGs with complex skill and equipment systems, and from a point of sheer quantity, nothing modern comes close to Morrowind. It has a whopping 16 equipment slots, including the ability to wear clothes underneath armor, where your average modern RPG just has one slot each for head, chest, legs. Also the variety of weapons: you had swords, axes, maces, spears, bows, crossbows, throwing weapons... nowadays you usually just get bows for ranged weapons, that's it, and spears are even rarer.
I also like choices & consequences, and while those have become more popular recently, the sheer quality and quantity of Arcanum's C&C is unsurpassed. This game's C&C isn't as heavily telegraphed as in modern games, and goes beyond being a simple forced binary choice at a specific moment of the story. The steam engine quest in Shrouded Hills is a perfect example. No modern RPG comes close.
In strategy games, I love a simulationist approach to combat, but those have declined too. Total War's battles peaked with Rome 1 and Medieval 2, modern iterations of the series don't even try anymore, the combat system has been horribly dumbed down. My beloved castle building sim Stronghold has been stuck in the sad limbo of trying to replicate the first game's success but always falling short. And even the new Men of War sequel is worse than its direct predecessors. It's weird how many games had excellent entries in the past, but their sequels lower the bar instead of raising it. Why would I play the newest game in a series when the older one is better? Many such cases, especially in strategy games.
All of these observations are based on objective, quantifiable criteria. Thief's stealth systems are the best ever made, nothing surpasses them. Deus Ex's level design is objectively great, few games even come close. There's no subjectivity here. It's all facts.
