Sure. Nextcloud GmbH seems to be one of the winners. It sells a customized version aimed at government agencies.

- https://en.wikipedia.org/wiki/Nextcloud

If what they sell is the open source Nextcloud, it is a horrendous product.

Its architecture is weird, with a proxy inside you can harden only by editing data inside a container that is volatyile by design (and has to be). There are numerous issues opened on that topic, Nextcloud response is "live with it".