I've never used nextcloud, but I always imagined that the point is you can run services but then plug in any calendar app etc. You don't have to be running nextclouds calendar, I thought. Did I misundestand how it works?

If dav works best for you, you're using it right.

I would assume that the people for whom a slow web based calendar is a problem (among other slow things on the web interface) are people who want to be using it if it performed well.

They wouldn't just make a bad slow web interface on purpose to enlighten people as to how bad web interfaces are, as a complicated way of pushing them toward integrated apps.

Their calendar plugin provides CalDAV, so you could just use your local calendar app that syncs with the server over that protocol.

Sooooo why not just host any caldav server instead? Like, why is nextcloud so popular compared to self hosting caldav?

In my case, I want file/photo syncing, calendar syncing, and contact syncing.

Nextcloud provides all 3 in a package that pretty much just works, in my experience (despite being kinda slow).

The Notes app is a pretty nice wrapper around a specific folder full of markdown files, I mostly use it on my phone, and on my desktop I just use my favorite editor to poke at the .md files directly.

Oh, and when a friend group wanted a better way to figure out which day to get together, I just installed the Polls app with a few clicks and we use that now.

I am a bit disappointed in the performance, but I've been running this setup for years and it "just works" for me. I understand how it works, I know how to back it up (and, more importantly restore from that backup!)

If there's another open-source, self-hosted project that has WebDAV, CalDAV, and CardDAV all in one package, then I might consider switching, but for now Nextcloud is "good enough" for me.

Ok so it's just the convenience of being a package, thank you for explaining.