I think at lower levels it can mean a lot of things. In my experience, it’s usually more often like a blocker bet than pure strength. People catch a little bit of equity and are trying to take control of the pot and draw for a bit cheaper. Sure, some guys will donk a flopped straight or two pair, but I think most low level players are more likely to try and check-raise a monster than lead. I guess it depends on where you play.
I hope Brad weighs in on this because it’s interesting. Personally, I’ve donked flopped sets, draws, and complete air (board comes 3 low cards, pretty sure villain has big ace, so I bet to take lead and not let a high card come off on the turn for free). For me, this is often villain dependent and I often exploit certain player types. I’ll do this when I play 2-3, but this isn’t something I do often when I play 3-5.
I think there’s certainly a spot for it in your arsenal, but it depends on what you’re trying to accomplish. It’ll be interesting to see what others have to say about it.