https://peakd.com/hive/@brianoflondon/gab-quietly-dumps-experiment-with-decentralisation-just-another-web-2-0-site-now I wrote about this at the time. The full post from Gab at the time is quoted there. The TL;DR is that Mastodon becomes a hideous resource hog at scale, and this is almost an ^n problem with federation. If you want some fun, post a link on a Mastadon site and then watch as dozens of instances all download it simultaneously. If a popular account shares your link it's like a DDOS attack. Quote: The ActivityPub model represents an amount of load and cost that is disproportionate to the Gab community's use and realized benefits of it. In terms of value for value for the Gab community, there is no clear way to justify further participation in the ActivityPub/Fediverse experiment. Additionally, our community is not pressing us to invest in it at a loss because they love it's vision and want to build in that direction. Gab is, therefore, spending too many dollars from sources who don't use Federation services at all or care about them in any way. That is not fair to the people who spent those dollars hoping for a better or more stable system that they want or need to use.