...I mean, the 3070/3070ti/3080/3080Ti are still slightly more powerful than PS5s and Series Xs which will be the baseline for most games for at least another 4 or 5 years. The 40 series being a notable step up isn't going to change that. So yes, a 30 series card will no question be fine for at least 4 years unless you're the kind of person who wants 4k ultra settings on every single game they play no matter what.
I agree that those cards are fine in 4 years if you don't max out, but a GTX 1070 (from 6 years ago, which is the same as the RX 3070 in 4 years since it was released 2 years ago) is not really good right now.
Would love to have a conversation again in 4-5 years with people that have an RTX 3070 (ti). I know how it felt owning a GTX 680. Everyone said 2GB is enough for the next 6 years. Spoiler alert nobody was using a GTX 680 anymore in 2018/2019.
But I do think we are kind of arguing two different things. I am well aware it is easily possible to run a card for a long time. I survived 6 years with an R9 290X. Some few people with 1080p and 1440p monitors will still game in 2026 on their 3070.
At that time again the power draw in relation to performance might even make the 3070 a more expensive product then. At least for me in europe where I no with an absolute smile on my face can pay 4x the electricity prices that people in the US pay.