Especially because this is a hobby for most homelabbers, I've never understood why people insist on opening it to the internet.

Visiting various subreddits, people massively underestimate the amount of time required to host something in a secure matter, and just because their little corner of the internet hasn't been hacked yet doesn't mean it's safe.

Self hosting stuff means you have a side gig as an unpaid system administrator. Sharing it with other people also means you have a SLA.

I self hosted for decades, but 5-6 years ago I simply put everything important in the cloud. The only things I host at home are media and my home assistant, and access to that is guarded by a VPN. I have a site to site tunnel between my home and summerhouse to allow media streaming there, and otherwise it's just regular road warrior tunnels. Using wireguard allows me to keep the VPN up 24/7 because it supports routing only specific subnets as well as auto disabling on predefined networks.

I also "host" backups at home. Everything stored in the cloud is backed up at home, as well as with another cloud provider.