“Mozilla has renewed its promise to continue supporting Manifest V2 extensions alongside Manifest V3, giving users the freedom to use the extensions they want in their browser. Despite the intentions, Manifest V3 places restrictions on certain types of add-ons, like ad-blockers, that can render them less effective. As Manifest V3 enforcement is rolling out, extensions not compatible with it are being disabled from people’s browsers, depriving users of the choice of functionality over risk.”
I moved back to Firefox about a month ago, not due to the Manifest V3 roll out, but rather because the mouse right-click was broken on Brave browser (it kept triggering the menu actions when I released the mouse button).
I can say that everything I need to do, works just fine on Firefox. It also has a very rich selection of extensions to choose from. Firefox actually had vertical tabs before Chrome did, which an extension implemented very well.
Firefox, not being Chrome at all, is also a positive factor for many.