It’s not a conspiracy. It’s been a very well published and discussed process.

There are exceptions but browsers are either reconfigurations of firefox, like librewolf, or reconfigurations of google chrome, like vivaldi.

Some dweeb will be along in a moment to tell us all how vivaldi is not merely a reconfiguration, but the point is …

google changed the manner in which plugins can interact with the web page you see. In recent months you could re-enable the old plugin interface by recompiling with a different configuration, but once google makes a change that breaks that old interface then you can’t just re-enable it.