When the “large” voices leave in significant numbers - in the UK it is used wildly by public sector and charity organisations, there are official governmental Twitter accounts, all the broadcasters have accounts.
Really wish I could convince local government entities to switch to Mastodon - my local police said it was "subject to O.P.R.A." and needed to meet retention rules (if you rolled your own...), and the state wildfire commission said they were looking at Threads :/
So instead, both are still stuck on the platform that requires a login to see posts and filled with nazis.
I think Threads federation may actually help with. I’m trying to persuade a health body at the moment to switch from Twitter and to roll their own Mastodon instance, based on the fact that what they really want is the widget on the website, control of their data and the ability to reach people.
Twitter has already screwed the widget with the login/authentication requirements. If
Threads actually allows its users to see Mastodon posts, that’s a big old reachable audience.