Nextcloud is AGPL, that ensures when using an external hosting provider you still has the freedoms, access to source code (their modifications) and the setup is

Nextcloud is AGPL, that ensures when using an external hosting provider you still has the freedoms, access to source code (their modifications) and the setup is portable. It can be very buggy and slow, especially the addon apps, but after years of usage I cherry-pick the functions that works for me from those that are too basic or unstable. The experience of Nextcloud is very uneven.