I agree. This is simple & stupid a problem. It's grossly anti-user. But today, security rules, and security sees all the misdeeds of users, and those who would prey on them, and they have no emapathy left for creativity and fun. There's no moral-value-party left anywhere that defends user freedom, that is pro end-user-hacking.
The Manifest V3 (MV3) catastrophe is still scheduled for 4 months out, even though there is still only 1/3rd the work done thay it would take to allow GreaseMonkeyTamperMonkey/et-cetera to live. The new browsers are actively unwinding power & possibility, forever trying to undo the permissiveness that it had (ex: CORB, and now ORB). The standards authors & browser makers are infected with deep deep fear. Certainty & closedness is winning.
Userscripts will run, but if they try to load any content from elsewhere, that breaks. So, for example, the Hypothes.is extension wont load. Affected sites keep growing. https://twitter.com turned on CSP many years ago.