1) Get a Synology NAS.
2) Install the 'Synology Drive' package
3) set up 'Quickconnect' (~DDNS)
4) Remote backup can be though a number of providers (e.g. Backblaze) for cheap
No monthly fees. No domain needed. Storage is as cheap as the HDD's you stock it with. Your hardware and all your files are in your own house. Everything on BlackBlaze can be encrypted. You can set it up all through a webpage-based-GUI.Technical, non-experts in computing stuff can do this. Not quite simple enough for the general public though.