And if you think someone you follow boosts too many things but you still want to see their posts, you can follow them without boosts:

https://fedi.tips/hiding-someones-boosts-in-mastodon-without-blocking-or-muting-them/

I'd never thought of that, but that makes sense.  Yeah, here, a favorite just means "I saw that."  I usually favorite something if I'm already boosting it anyway, though, just because I'm more likely to look at something if it already has a huge number of favorites, or boosts, or both; I assume a lot of other people are probably the same way.  I don't even think it's a "bias" or whatever, so much as I'm just more likely to notice it, even if it wouldn't have caught my attention otherwise—especially if it's a long text post that I end up bookmarking if I don't have time to read it immediately.

Boost = I liked your post and think other people might appreciate seeing it.

Favouriting a post does not push it in other's Home feeds, because there are no algorithms doing this (on Mastodon at least).

So people favourite only, thinking it's enough to help increase reach, but it isn't. Boosts are what keeps the Fediverse alive and moving

Are people stingy about boosting, or something?  Because that's silly, lol.

I boost every post I've already bothered to look at, unless I have a specific reason not to boost it.