Browsers based on chromium do not have to follow exactly what the main branch is doing.
If they want to keep supporting MV2 or support different rules for MV3, they can. Albeit it's a bit cumbersome.
yup, I use Vivaldi and will never use another browser. has everything I need right in it. built in ad blocker and tracking blocker, integrated with the Fediverse, insanely customizable, and it's lighter than firefox. I like firefox but i find it to be a ram hog.
It depends. It will not affect many of them until 2025 when enterprise support for v2 ends and by then other arrangements and fixes might be. Brave in particular I would not worry yet.