You're misunderstanding the issue. As much as "RTX OFF, RTX ON" is a meme, the RTX series of cards genuinely introduced improvements to rendering techniques that were previously impossible to pull-off with acceptable performance, and more and more games are making use of them.
Alan Wake 2 is a great example of this. The game runs like ass on 1080tis on low because the 1080ti is physically incapable of performing the kind of rendering instructions they're using without a massive performance hit. Meanwhile, the RTX 2000 series cards are perfectly capable of doing it. Digital Foundry's Alan Wake 2 review goes a bit more in depth about it, it's worth a watch.
If you aren't going to play anything that came out after 2023, you're probably going to be fine with a 1080ti, because it was a great card, but we're definitely hitting the point where technology is moving to different rendering standards that it doesn't handle as well.