You are comparing apples to oranges here. For now Logseq export is just a static website. We hope to make it more dynamic in the future, the indieweb direction is promising. ActivityPub albeit very nice, is not something even in the picture.
The goal of Logseq is not a twitter wannabe, it is to use, and later share knowledge, not as short-term chat, but as long term collaboration. Mastedon and Twitter have there place, but neither are suited for long-term knowledge work. Best would be a semi-static setup. Static so people can depend on it staying in place, being able to link to it, semi- for cooperation and backlinking.