You definitely need a little bit craziness and unpredictability to make a truly landmark game.

This might be an unpopular opinion, but I think truly good games (the ones that go down in history) need a certain amount of jank. Not jank for jank's sake, but because something new, that makes you go "wow", cannot have the same true and tried game design/gameplay approaches that have been done before.

Just look at the classics, they are considered milestones, but they have a lot of issues:

• F01 / F02 - It is very easy to mess up your build, but the flip side of this is you have a living world where you can play as a slaver, play as a character with development disabilities and discover a whole new approach. Even if you've played the game many times and are comfortable with older CRPGs, the early game can be a slog. I find I constantly have to kite and use cheese tactics in the first ~20% of the game.
• VTMB - Combat was generally subpar, especially if you went with weapons. Many abilities/skills were unbalanced. Late game was subpar.
• Deus Ex - Early to mid-game combat is a bit of a slog and considered unpolished by modern standards (but the flip side is that you feel the progression). Some of the stealth gameplay can feel a bit cheesy. I would argue weaponry is unbalanced. Arcanum - Picking the industrial direction resulted in much more tedious and difficult gameplay than going with magic. Both real-time and turn-based combat was shit.
• Morrowind - For some of the quests, I literally had to almost try a "point and click adventure" approach to figure out how to complete it. I was never a fan of the combat in Morrowind.

And yet I strongly prefer this approach (and modern versions such Space Wreck, Age of Decadence, Colony Ship, Consortium, New Vegas, UnderRail) to Obsidian's recent output (let alone Bethesda with Starfield and Fallout 3).