Buying midrange often vs buying flagship once in a while

What do you guys think is better for the 40 series or even 30 series as it stands today? I'm on 3440x1440 (AW3423DWF) with 5800x3d (b450 tomahawk max) and 32 gb ddr4 3600 ram on a Corsair rmx 850w psu. I was thinking of either going 4070 or 4070 ti and having to potentially upgrade to a 5070 due to vram limitations (12 GB) or just getting a 4090 and be done with upgrading for at least until the 60 series in 2025. What would you guys recommend for me? Which route offers the better value long term? Upgrading often but paying less each time or going big for a huge upgrade every once in a while? I plan to play a variety of games including cyberpunk with ray tracing enabled, Forza 5, god of war, Diablo 4, overwatch, and warzone. I think usually the midrange is the smarter way to go historically, but this gen I read it's worth it to go all the way to the top with the 4090 because the midrange value isn't that strong because of the low vram buffer 12 GB for the 70 series cards. The 4080 is just bad value to me as well and I will probably not consider that card as an option for me. Leaning 4070 ti vs 4090, or even the 4070, but I think that might be too weak for 1440p ultrawide.

Update: thanks for all the replies, happy to report back that I just bought a 4070 ti for $665 open box! I think that is a pretty good price to performance GPU for my needs without breaking the bank. Although I would love the 4090, spending $1k more was a tough pill to swallow for me, especially at ultrawide and not 4k resolution. Hopefully I don't have buyers remorse. Now I hope it can fit inside my Nzxt h510 mid tower with a front radiator installed...