Blocked after two months of a positive reunion and amazing dates...How do you all feel that anyone can establish trust with anyone in the future?

For context, I (32f) had reunited with someone (37m) a few months ago whom I had previously tried to date several years ago. It didn't go well then, and we had a falling out, but this time around, we hashed things out and cleared the air. We both communicated how much we had grown over the years through therapy and general life experiences, and how we were looking forward to a fresh start. This was all communicated before we had agreed to date, let alone see each other in person again. Eventually, we went on several months of amazing dates, communicated on a regular basis, consistently talked about the future, and made plans for the following weekend.

A few weeks ago, I stopped hearing from him, and I learned he blocked me after I tried reaching out. While I'm shocked, I at least know there is finality to this. I'm no longer left wondering if or when he will reach out again. It is what it is.

However, I'm curious, what leads people to just block or ghost like this suddenly? This is my first experience of dating someone who has ghosted, let alone blocked me, outside of someone I've gone on a first or second date with. There was no attachment there, so to me, no hard feelings in those instances. However, this feels like a sudden 180, especially when someone's demonstrated that they were a good a communicator. I imagine in this modern dating world, this also makes it hard for all of us to establish trust with future partners...we all want to believe what the other person says...but then when consistency and communication vanish suddenly, it's hard to trust anyone moving forward, right? How can we all stay optimistic with the hopes of finding our partners? Or, how do we adapt to this type of dating today? It seems so brutal, despite the acceptance I'm having in this situation.

I guess I'm not looking for personal advice, just a general discussion on establishing trust with prospective partners.