Hi OP,
Dating isn't how it used to be - it's easier than ever to get exposed to huge pools of available women via O.L.D and they'll throw the bait out there to chat to the ones they're somewhat interested in - though usually to multiple people (as we all do to improve our chances i.e cast a wide net), they'll continue chatting with them all until one they really "like" (which doesn't mean love but it could be something more sinister like a woman with tons of cash or even simply convenience e.g. lives more locally to them or has a "simpler" backstory (no kids, etc) whom they presumably zone into, by which time you get ghosted. They profess feelings before to you as if the other person might not have come along, they might have pursued you.
Alternatively, they are not serious about meeting anyone on there as they're already in a relationship or like being single but do the whole chat romance thing just to stroke their ego and reinforce that they can have anyone they want.
I've seen that a lot of them will initiate conversation repeatedly, keep complimenting me, etc but when it comes to meeting up, they either postpone it multiple times or are hazy about setting an actual date and time to meet... which I found unexpected (would make more sense if they did that after meeting, etc) so feels like they get scared when it comes to actually meeting as they'll still continue having endless text and phone convos (or perhaps they're not single)..
By the way, I am not anything terrible (mid-20s, told I'm pretty, quite well established in career, etc) and these men aren't anywhere near perfect lol so it's very unlikely to be that you're not worthy.. more that you're just unlucky with the ones you come across but it's fairly the norm now with internet dating.