I've been thinking about this the last few days after someone pointed out he gets a lot more engagement on Bluesky.

One thing I still think not all people account for is that as far as I can see:

- followers on "older" accounts on Twitter probably includes a lot of accounts that will not create activity, either because they have been outright abandoned or because they are used read only (this last effect is probably amplified because twitter now demand people to be logged in to see replies).

- I'll also suggest that it is reasonable to think that the most enthusiastic part of the userbase will be the first ones to join a new platform

Right, that's the point, follower counts on Twitter aren't meaningful anymore because it's a deprecated old platform with all the cruft of a long history of abandoned accounts, forgotten bots, spam accounts, etc.

Wouldn't the Twitter account be likely much older, and therefore have many stale/dead followers?

The reason is pretty much irrelevant, either engagement on Twitter is artificially lower because of algorithm shenanigans, or because it's becoming a ghost town of abandoned accounts and spam bots. Neither option is a compelling reason to stay on Twitter

I wonder what's the motivation for a normal person to leave replies on Twitter anymore. The top replies will be porn spam and other blue check self promotion bullshit. In hindsight it makes sense the people left on Twitter would continue to post into the void but not engage.

That pay-for-attention reply prioritisation thing really was the most bizarre product decision. Like, everyone already knew it didn’t work; dating apps have been dealing with the problems with pay for attention for about 25 years now.