If you enjoy someone's post on #Mastodon go ahead and click the star. If someone tells you that's meaningless because there's no #algorithm, ignore them. Sure, boost the post too if you want others to also see the post, but don't think telling someone you like what they posted is somehow unimportant. In real life I don't tell someone, "good job," or "well said," or "I love that," for the sake of some algorithm, I do it because I'm human and they are too. It's fundamental to being truly social.
@tuckerteague Yet another way Mastodon is following in Tumblr's footsteps. There, it has long been common knowledge that likes do nothing to increase exposure but still feel super nice. I star/heart things that tickle my fancy; I reblog/boost things that I think my followers will enjoy. Lots of overlap, but definitely separate things.