I've also been there... why are some blokes such arseholes?!
I had a FWB who I thought (note the "thought") I'd fallen for, even though he'd also kept me at arms length for a couple of years. I was convinced he'd eventually see he wanted to be with me. He didn't ghost me but it was clear he really did just see it as a FWB thing and was never going to look at me that way.
It hurt. It really did. But cutting off the communication did help. Over time I re-learned who I was and once I started liking myself again and realising that just because he didn't want me, didn't mean no-one did, I ventured in to the world of online dating.
I found my now DP on there and haven't looked back. It's amazing knowing there's someone who really does want to spend the rest of his life with me and I realise that my ex-FWB was just a stepping stone on the path to finding my DP. If I hadn't had the experience with him it wouldn't have led me to the same choices (a sliding doors moment perhaps?!).
I'm now back in contact with my ex-FWB as we were friends initially anyway and we're back to being acquaintances. I now look at him thinking "thank fuck for that!" Don't get me wrong, he's a nice bloke, but so, so selfish and even if he had committed we'd have been split up by now and it would have been even more time wasted.
My long waffling is to say that I know it hurts but listen to all the PPs who say it's him that's got a problem... not you. You deserve so, so much better and you're better off without him.
I'd probably not reply to him. If he then follows up on it just reply "I did get your message. I just didn't think it worthy of a reply" then block.
Look after yourself OP...