Honestly can’t remember at this point. I also tried both and couldn’t decide back when I was comparing.

I think I started with gotify but struggled getting it working with one of my use cases and ntfy was able.

I don’t know if things have changed so I guess try both and see what best suits you

I personally chose ntfy over gotify and use it everywhere

P2p mesh?

Flash thingino on a supported camera and you have an open source firmware available with vpn support