The lowest? I think Skylake 6th generation is getting too old, all-around. I would feel like I'm buying a brand-spanking new Oldsmobile (Olds is defunct since 2004).
I would get the highest level I am willing to pay to make some so-called future-proofing. BUT you run the risk of locking yourself to a cpu-mainboard from two generations to the next ones. For example: I can't put an i7 10700K on my new and modern Z390 board. but I was already aware of that. So I would look into component upgrade compatibility before buying. I have 9th generation hardware and definitely can't complain, even though it's locked there. You're right: a fraction of a second is meaningless here.
Intel is having so many problems right now with its technology and personnel, it shakes my confidence a bit in anything coming out in the near future. I have no personal experience with AMD but a lot of people on Steam are sporting some amazing Ryzen builds for considerably less money than Intel counterparts.