Twitter Blue, a $3 monthly subscription service, could be coming soon

700 comments when the news broke two days ago https://news.ycombinator.com/item?id=27316115

I am curious if stagnate user growth could cause these companies to revert to a subscription model, but I suspect there's lots of plans to avoid that.

So it is the ability to undo, and sort tweets into collections. Not a twitter user, so very curious for those who are - is this worth $3 a month?