Having played a lot of games isn't really much of a qualification, is it? I'm curious about your claim that Unity games "always feel janky". Which games gave you this impression?
And yeah, I feel like you're choosing some specific games while ignoring all the others. Tons of famous Unity games are great. Is Subnautica janky? What about Hollow Knight? Rimworld, Beat Saber, Outer Wilds, Cuphead, both Ori games - the list of major Unity projects can go on for a while, and I wouldn't call any of the above examples janky.
Yes: I could make the crashed burning spaceship pop into and out of existence by walking a couple of metres back and forth across the floating platform I was standing on.
And even then, as far as I know, they're not really simple 2D games, but more of 2.5D. There are 3D background layers and 3D-like lighting and effect calculations, in addition to overall being very visually dense and complex. I certainly can't compare it to fully flat games, like the aforementioned Hollow Knight or Cuphead, etc.