This really depends on what kind of target you are. Are you a random person on the internet? Then making yourself a smaller target by using obscure services might help. Are you someone with sufficient value for a spear phishing attack? Not so much. “Sufficient value” might just be “you slighted the wrong person on the internet.”
There’s also a lot of trade offs involved, some of them less than obvious. For example mastodon servers may be run by a person/team who’s trustworthiness rating is harder to evaluate Tran facebooks. The server you’re on might by run by well-meaning but incompetent people. The server you’re on might have one participant that is a target of sufficient value for spear phishing and your data might be taken and leaked just to obscure the real target.