The impact was massive attention to alternatives. Tons of traffic testing on said alternatives. Tons of press to activity pub, etc etc.
It’s just like Mastodon. Every exodus was big for mastodon and activity pub. It gained traffic, interest, devs and users. Did it kill twitter? Of course not, but only fools thought it was likely to.
Killing some massive social network is near impossible. But dismissing the twitter or Reddit drama as being irrelevant because they didn’t die is missing a lot of interesting development in the FOSS ecosystem imo.