In normal times, I'm thinking the 4070 should be selling for more like $400 rather than $600. I hear it is not selling. Maybe the market will respond accordingly. ITMT, my ancient 480 8 Gig can run almost anything at 1080p on good settings at 60 FPS. If it dies before I'm ready to pull the trigger on something? One can find a 580 8 Gig for around $100. That will suffice till something better comes.
You can get a used or refurbished 2070 for like $200 and it'll play most games at 1440p medium/high at over 100fps.
Most games have DLSS or Fidelity FX and that is going to massively extend the lifespan of these cards.
I currently have an RX 5700xt which I've been running for 3 years. Its performance falls somewhere between an RTX 2060 Super and an RTX 2070 (and sometimes beats the 2070's performance depending on your resolution), and that card is still going strong. I use two 1440p 144hz monitors and it drives them at over 100fps absolutely no problem in the vast majority of games. And for any games where it can't I crank up Fidelity FX until it can.
If all you're looking to play at is 1080p and are willing to drop your settings to medium instead of ultra then the RX 580 will play everything on the market at 60+fps, which is a pretty great deal for something that's less than $100.