The ‘browser incompatibility’ is what’s written on the fallback page.
No. The page clearly says "Incompatible browser extension or network configuration".
It then lists a number of troubleshooting steps to get the page to work.
The question was about the problem that migration from Cloudflare would solve and I provided one particular problem.
I don't think so. Site maintainers are expecting your browser to run the scripts to detect and prevent abuse, and you are going way out of your way to not run them. You are not describing a problem.