Nextcloud was too slow and bloated for me. I used Seafile for years and it was fine, but at some point I went to some more simple setup : sftpgo to share folders (sftp, dav) and syncthing for the folders I want to sync between devices. You can also set ignore lists in syncthing to ignore large dirs. Keep it simple stupid 😅
Install LineageOS or e/os/ on your phone and bye bye Gemini 🙂