I'm in the middle of my umpteenth playthrough of New Vegas. Decided to configure the Tale of Two Wastelands mod so one can do Fallout 3 and then New Vegas in one go—putting 3 in the NV version of the engine.
I say singular "mod," when in actuality you need many of them to smooth out the experience, but man the main process for getting it working was involved. Kinda neat they made it all work, and the documentation was relatively easy to follow. It's just one misstep and you've got to delete it all and start again. The merging of the two games takes about as long as downloading both, seven though they're already on your local machine.
I tell you what, Fallout 3 in the fnv engine with hardcore mode on (only way I do FNV anymore) is challenging. Managing food and water in Capitol Wasteland is a right PitA. Also the DT system makes things …interesting. Everything is a bullet sponge. But you do get a mix of 3 & NV perks so you can craft AP ammo.
Thought about getting Cyberpunk 2077 since it's on sale, but I'd probably want to upgrade my CPU. Going from my ryzen 2700x to something like a 56/5800X3D (drop in upgrade) would net something like a 1.8x performance boost. I've stuck with it as long as I have, because I just don't play intensive (i.e. new) titles. I also don't want to/can't build a new system, mostly because it would force all upgrade to Windows 11. When 10 finally goes dark, I'll probably just move to Linux.