> I can easily install an ActivityPub server, with Glitch.

Can you? The same Glitch that shut down last year? https://blog.glitch.com/post/goodbye-glitch

Regardless, ActivityPub and ATProto have different designs and goals. Your question is akin to comparing a helicopter and an airplane.

There's no such thing as a "ATProto server". How complicated it is, and the trade-offs it made are valid criticisms of it. It all depends on what exactly your goal is as a participant of a distributed social network.