The operative word here is "seem." You "seem" to exclusively attract unavailable men. Only in the case of men in relationships can you be sure they're unavailable. As far as the other two categories, it sounds like you're making assumptions based on behavior you perceive as inappropriate or unavailable. You're not in the heads of these men. You don't know what is motivating them. You're assuming to know because of either previous negative experiences or an internal bias. Real talk: those last two categories on your list are otherwise known as "dating."
I hate to be the bearer of bad news but A LOT of people are only looking for someone temporarily or prefer to juggle multiple potential partners until their next relationship. That's how many people actually find a relationship. They enter into a situation unsure of exactly what they want, let things unfold organically, and then - BOOM! - they're in love. Not everyone sets out with the specific intention of finding a partner. There are tons of people that date just to date, believing that - when they find the right person - they'll commit. There's nothing wrong with that. In fact, that's an approach I recommend. You can have the long-term goal of a relationship while dating casually in the short-term.
Sometimes you just have to go with it. Heading into every date wondering if this person could be the one that makes you delete your profile is a tremendous amount of pressure to put on yourself.
It's called online dating for a reason. These platforms exist to help people get dates. Whether or not users find a long-term commitment is up to them. Take it all one step at a time. Dating is supposed to be fun.
This, in a nutshell, is one reason so many people get frustrated by online dating. They don't want the people that want them and would rather focus their efforts on matches that don't reciprocate their level of interest. Or they go after people with a ton of options hoping that person will decide to settle down with them. Most people on dating apps are drawn to the unavailable matches because we want someone other people want, too. We see those that take initiative as unappealing when, really, those are the people that hold the key to us getting what we want.
I think the real issue here isn't that you only seem to meet unavailable men but that you ignore the men that are available. It could be you prefer to be with someone you perceive to be in demand. There were (and still are) women that found Ted Bundy wildly irresistible. Being desired by others is not necessarily an indication of character.
Too often we focus on the external factors - what we'll look like together, the envy we might incite among friends, the photos on social media - and let them drive how we choose mates. I don't think I've ever seen one relationship like that end well.
My advice is to stop head-hopping or thinking you are a mind reader and get to know someone before you decide they have a game plan or agenda. My second suggestion is to widen your net and give those guys you deemed "maybes" a chance. Forget about what it looks like and hone in on what it feels like to be with someone that makes you happy and treats you with respect.
Good luck!