How can they move on so quickly?

My ex and I (both 29) were dating for only about 5 months. Early on, he pursued me strongly, told me he was only interested in seeing me, wanted me to meet his parents etc. I had some concerns over some of his behaviours (drinking specifically) but I never once doubted his loyalty. Looking back, there were some avoidant traits that I was probably overlooking. His texting wasn’t amazing - he could go 1-2 days without responding to me, but he was always willing to see me and seemed excited to spend time together. The communication lag got somewhat worse, but he still asked me to be his girlfriend in January.

In early February we spent an evening together where I brought up meeting his parents again. I booked a last minute trip for myself two weeks after this so we left the planning of dates in the air, but he was looking forward to meeting my parents, or so I thought.

Not three days after this date night my friend caught him on Tinder. When I confronted him he had no excuse, just said he was bored and it didn’t mean anything and it wouldn’t happen again. After I started asking more questions he basically changed his tune and asked for break, saying he needed time to think. He said he wanted time to focus on himself. We agreed to speak a week later, and I didn’t hear from him at all. When the time came for us to talk in person, he basically said that he wasn’t coming over as he needed more time, and I responded with some choice words on how difficult the week was for me and how appalling it was that he was taking no accountability for anything. Since then I’ve been ghosted and he hasn’t responded to any of my texts (I might honestly be blocked lol), and he unfollowed me soon after.

What I can’t understand is he’s literally right back on the dating apps, I made a tinder account to see if he’s active and he is, and my friend saw him on Bumble the other day. I don’t follow him on Instagram anymore but his follower/following count has gone up by a few since our initial break. This man isn’t the type to make 3-4 new guy friends in 2 weeks so I’m pretty sure it’s girls he’s meeting on the apps. I’m truly sitting here on my trip heartbroken and thinking about this man constantly and he’s literally moved on like it’s nothing. I’m just finding it so challenging to move on with no form of closure, no conversation about this, and the feeling of my relationship being completely normal and then falling apart in the span of one hour.

The cruelty of being cheated on is one thing but then them having no remorse and treating YOU like you’re the issue and then ghosting you while rebounding immediately is just too much. Why are they like this? If anything this has taught me that I you could be the most loving partner to someone, and if they aren’t happy in themselves or have avoidant tendencies, they can still dismiss you like it’s nothing…

Anyways this breakup is still fresh so please tell me it gets better 😭