The windows 11 cpu requirement isn’t a requirement per se but a “it’s validated to work on this or newer”. 6th gen Intel is no problem. Even 4th gen or older aren’t a problem, performance wise. The problem is the mandatory TPM 2.0 support. Intel CPUs only massively support that from 6th gen on and AMD CPUs even later (I think Zen 2). On some older boards you might have luck, especially if you buy a hardware TPM but my PC for example, running a i7 3770, only has a TPM 1.2 and no way to upgrade to 2.0. Now, there are ways to circumvent the need for a TPM all together on Win 11 but tbh, Win 10 installs perfectly well still on Hardware as old as Athlon 64 and in my experience even better than 11 anyways.