They don't represent any tendency or constituency of reality
All new X accounts have Elon as their first follow. This is like when iTunes forced everyone to have a U2 album. U2 suck but far less then Elon.
Cool. Places like this will probably work quite hard to not get sued by say, the Premier League, by not showing every game live, unlike Twitter. Makes me wonder how long Twitter can actually survive.
I wouldn't be surprised if he started to try to acquire other businesses to meet future roadmap features. They don't have the devs to build things like payments etc. But would you sell to Musk if the offer was equity in X? Some would.
No need to mention Liverpool. Never in a billion years will that happen.
A significant aspect will be where the journalists choose to break their stories. The stories people talk about. Im sure the papers/channels will be present on both but where they break live news will be interesting.
One thing to keep an eye on is "Active" users or accounts. People won't delete Twitter accounts, but they may use them a lot less. Threads will likely be paid for by ads, and will probably be more feature rich than BlueSky, so they will likely easily beat the numbers.
Lots of reasons one might do well over the next. Friction to move a community can be massive. Perhaps Twitter will stay far bigger than all the rest for a long time, but for sure its makeup will change. Twitter seems to be wanting paid users rather than advertising. Only so many people want to pay.