IMO this is not a reasonable thing to expect of people. Boosting a post comes with a cost that liking doesn't, namely the attention of one's followers. There's a big difference between "I like this" (or "I'm glad you posted this" or "I empathize" or any of the other various meanings of liking) and "people who follow me will want to see this". Plus, there can easily be too many posts crossing my timeline (using myself as an example) that would be of interest to my followers and I might want to limit my boosts to only the most interesting ones or a particular mix of topics or so on.
(The snarky response, of course, would be that I'm happy to stop liking your posts unless I also boost them, but TBH I don't even think I could remember to do that.)
#Fediverse #Mastodon