Though I'm not sure I understand the reluctance for cloud. Amazon prime photos is by FAR the least expensive way to maintain a complete backup of all my raw files (even if I don't use their tools as my primary way of cataloging the photos)

(I have my synology Nas set to automatically upload my photos to Amazon - I pay less to store 3TB of photos there and gave immediate access to them that I would to put them on hard drives in a safety deposit box or to back them up myself to any cloud storage like even Amazon glacier... It is really a good deal for off-site backups)

You can also run Plex on synology