How do you get your flakey friends to commit to plans without sounding mean/forceful/desperate?

I have some friends that are very wishy-washy with me. I’ll say, “hey want to do [activity] on Friday?” and they’ll say “yeah, maybe.” Then Friday will finally come and when I ask if they want to do it, they’ll say “Dude, you know what, I think I’m going to this other thing, you can come if you want.” It really pisses me off because now I’m forced to either stay home and sit on my ass or go do whatever my friend wanted to do.

I know that “maybe” is just code for “maybe I’ll go if something better doesn’t come up” and it’s extremely rude. I want to straight up respond by saying, “no maybes, it’s yes or no” but I feel like that makes me look like an uptight prick, like I am so desperate to hang out with them. It’s not that, I just hate having plans broken and getting stuck doing nothing.

So how do you handle flaky, wishy-washy friends? What do you say to prevent friends from flaking? How do you react when a friend does flake out in a mature manner that makes them reconsider their rude actions?