It's not if. It's when. It has been 'when' since 2020. It is coming. It is not going to not come. It will be here in mere releases. Get ready.
Something around 8% of total digital ad spend.
It's because they were literally sued and are not allowed to remove it, not because they don't want to.
I have a simple tab organizer extension and some greasemonkey scripts that should work perfectly fine on Firefox without any changes.