Why people self-host Nextcloud
Nextcloud is a broad personal-cloud suite, not just file sync. It can cover files, calendars, contacts, photos, office documents, sharing, and many extensions in one familiar interface.
The tradeoff is complexity: broad capability means more moving parts, tuning, and upgrade care. Use documented background jobs, database tuning, and external backups before giving it critical data.
Deployment notes
Nextcloud is listed with support signals for linux, docker. Check the upstream documentation before exposing it to the internet, review authentication defaults, and keep backups outside the primary host.