Can you specify what specific problems you are having? There have been many discussions regarding font issues in Big Sur and Monterey. I haven't working in Graphic Design since...well, never mind...so I'm not familiar with the current state of 3rd party tools. But as far as I can tell, that current state of 3rd party tools is just atrocious.
Font Book is a great example. It's pretty basic. It doesn't do much. But Font Book is just a basic user interface for a larger set of low-level font APIs in the operating system. The biggest problems that I've seen have been 3rd party tools simply aren't using that API. Consider a pretty basic feature like identifying one's favourite fonts. Font Book can do that, and has for years. But 3rd party tools don't support Font Book's font collections. That alone would solve all problems that I've seen.
Another problem are the hundreds of "Noto" fonts that seem to drive people to apoplectic fury. But it turns out that these are document support fonts that 3rd party tools aren't supposed to show in the first place. I got tired of arguing with people about it and just wrote a little app to fix it.
But the key part of all this is that I was able to find out what the problem was, demonstrate who was a fault, and write a demo app that showed how it should be done. That took 9 minutes. Publishing a a full-fledged app to fix the problem took a few hours - a few more minutes to fix the problem, setting up web sites, buying SSL certificates, setting up an App Store page, waiting for Apple App Review, etc.
But you have to ask yourself, or maybe, ask those 3rd party vendors, why some random person on the internet can definitely fix this problem (in their apps) in a few minutes, while they leave their users struggling for years.