Your CPU isn't supported and capable to run Windows 11.
Microsoft had tested all the CPUs and probably, they didn't got good results from your one.
Even though your CPU is powerful, it may not have the features and performance that Windows 11 needs.
Read this:
The compatible CPU list will not be updated. But you can log your thoughts as a suggestion in the Feedback hub. Microsoft may change it's decision. Less chances though.
Regards,