Why do so many men get in relationships and suddenly disappear?

Something I’ve noticed over the years and I want to understand why it keeps happening. Why do so many men get into a relationship and immediately fall off the map? They stop meeting friends stop replying consistently and everything revolves around the partner.

And when they do show face they seem different. Like they’re on some kind of leash. Every move feels calculated like they’re being managed or have to get permission just to live their life.

Is it weak boundaries from day one? Pressure from the partner? Or do some men just naturally deprioritise friendships and independence the moment they’re committed?

Me personally I’ve never had this problem. I’ve always kept my balance and stayed solid regardless of who I’m with. But it’s something I keep seeing in other men and I genuinely want to know why.

Would like to hear from men who’ve either been through it or made a conscious effort to avoid it.