@hrefna @dev_m I think more efficient protocols didn't really catch on, because they would be trickier to standardize (and implement). AP is very universal.
I'd be curious to know what the overhead of JSON-LD would be here in comparison to using some kind of binary protocol (I'm guessing).
For what it's worth, performance does matter to implementers. Some alternatives to Mastodon on the fediverse explicitly advertise the fact that they're less resource intensive.