I self-host Bitwarden, hidden behind my firewall and only accessible through a VPN. It’s perfect for me. If you’re going to expose your password manager to the internet, you might as well just use the official cloud version IMO since they’ll likely be better at monitoring logs than you will. But if you hide it behind a VPN, self-hosting can add an additional layer of security that you don’t get with the official cloud-hosted version.

Downtime isn’t an issue as clients will just cache the database. Unless your server goes down for days at a time you’ll never even notice, and even then it’ll only be an issue if you try to create or modify an entry while the server is down. Just make sure you make and maintain good backups. Every night I stop and rsync all containers (including Bitwarden) to a daily incremental backup server, as well as making nightly snapshots of the VM it lives in. I also periodically make encrypted exports of my Bitwarden vault which are synced to all devices - those are useful because they can be natively imported into KeePassXC, allowing you to access your password vault from any machine even if your entire infrastructure goes down.