that depends on that you do, going 8gb to 12gb is a good uplift.
i used a 3070 for a long time and never had any memory problems.
both of the kids pc's and 8gb cards and they game, and again they have never had a memory problem
I had a 3070 several games I played I had problems with.
I was playing at 1440p, Fallout 76, would run at 140 fps most of the time, then the FPS would dive now and then, 100% GPU memory use, thats completely unmodded as well. Both cities skylines games maxed the VRAM. Fallout 4 admittedly with mods, would easily get to 8gb use, dont forget that game was released in 2015.
The AMD equivalent at the time had 12gb and if the 3070 would have also had 12gb it would have been about right. Nvidia are right buggers for doing this, its nothing new.
I had a 1070 before that, which was heading towards 5 years old, that also had 8GB VRAM, the 1070 was released in 2016. Why now, in 2025, 9 years later is the equivalent card only shipping with 4GB more?
The only reason I bought that 3070 was because its was in the middle of the mining crisis and I had no other option really, the card (in my opinion) was a lemon, I got shot of it and bought a 7900xt and never looked back.
I don't think its acceptable at all, for a modern GPU that they are charging good money for to be shipped with the amount of memory they have.
Remember the more you buy, the less VRAM you have, the more you save...... or something like that.