We kind of selfhost almost everything - while we operate a small server ourselves, the main burden is on a dedicated server setup. Basically a FreeIPA+Authentik+OpenCloud Stack as a base,with Redmine, Kimai, Zammad, Matrix, Jitsi and a few mode apps.

Backups are done onsite and to three different offsites, including cold storage backups.

As we all work fully remote this setup is also fairly adaptable and the switch to a (almost fully) Linux shop went far better than expected - my staff is fairly content with their setup (afaik).

The only thing I refuse to selfhost are email and VoIP.