I never said it was generous, having more than enough doesn’t increase performance.
The likelihood of a 3070 being able to maintain 60fps at 4K using max/very high settings in future AAA games is unlikely, particularly when things like RT are enabled. It has the same power as a high end card released over 2 years ago which wasn’t that good at RT to begin with.
Games that are as well optimised as doom eternal are rare, most just aren’t. The requirements to game at 4K don’t sit still, it’s an ever moving goalpost and a 3070 will not keep up one way or another. True high end 4K pc gaming is an expensive hobby compared to 1440 and 1080.