The long and the short of it to me is, there will always be something around the corner and you'll never know how much of an improvement it is until it's in the reviewers hands. Everything improves, and computer hardware faster than other things. Additionally it's very simple to measure absolute improvements.
So, move to a new card IF you need a new card. That compelling event could be a new game, new monitor, new VR headset or that you've got a bonus from work and want to spunk a bit of it on a toy.
Don't spend money on hardware if you can't afford it or in reality you're happy with the status quo. That purchase will only bring short-lived joy as it will quickly be superseded by something faster etc.
I have a 3080 on order after cancelling a 3090 order as being too frivolous. I skipped the 20 series cards and have had my 1080ti for a about two years. My G2 headset is due to arrive in early November, so I have a compelling event. I'll be happy with the 3080 as I've watched various reviews and know it should cope with the new setup requirements.