The importance of the local feed shouldn't be underestimated - it's one of the reasons that the 'rglullis' communities have struggled (as discussed on https://lemmy.world/post/20236330)
Thats an interesting dynamic, which also influences the choice of instance: which instance gives my posts the most initial boost.
This also results in a soft network network effect between different fedi servers: servers with a lot of reach attract a lot of people because they have a lot of reach. Its necessary that the biggest instance implements counter measures here. Lemmy.world does that by selecting the all-feed as default in the UI. Threads doesnt.
The communick instances and communities were also managed by one single person, which probably did not help with the trust of the whole system
