FFS, so much stupid going all left, right, and center..
What are the WAN speeds involved.
Ubiquiti sells nice gear, but there are potential speed limits depending on router configuration.
UTM at home? WTF is the point of such a complicated setup.
There is no good free UTM anyway.
WTF are you doing for backups that is not already encrypted before going over the wire? You don't need a VPN for back ups.
You have an old Ubiquiti router but didn't say shit about the model. As mentioned it is a ROUTER, if you hated it because it didn't massage your dick, then that is your fault for not knowing WTF you bought.
There is not a single model of Ubiquiti router that cannot be upgraded to the current firmware.
Software routers are silly things that burn power and time.
So what should you do?
Depending on your WAN speed needs, buy a Ubiquiti or Mikrotik router that will handle the needed speeds. I personally recommend the Ubiquiti ER-X for "technical" home use first, then the Ubiquiti ER-4 if you need more speed with the QoS enabled.
For normal home use, I recommend the Ubiquiti Amplifi Instant Mesh System for $179.
Buy a RaspberryPi 3 kit with case and card for $50 someplace and install Pi-Hole. Setup your Router to send all DNS to the Pi-Hole.
Setup MeshCentral for remote support
Setup ZeroTier for any point to point "vpn style" needs you may have.