I didn't know they even had a VPN but I doubt I would trust them over Mullvad or Proton. Even if what other posters are saying is true and it is just a reskinned Mullvad i'd rather give Mullvad money over Mozilla.
Age is only part of the equation. Older ones can be more secure but you have to go further back and think of more than just the hardware. The big thing is to try to get a laptop that is sold using a non stock BIOS or be comfortable doing the work yourself. Libreboot; Coreboot; or something like it. After that try to use as free as an OS as you can such as Trisquel; Guix; Hyperbola; etc. There are lots of stores that sell laptops that are more secure out of the gate:
Basically a computer is only as secure as you are willing to make it. You are limited by the hardware but you choose the hardware so you're only really limited by yourself.
This seems more like a good reason to not use default options than a reason to not use Garuda. Many distros have worse defaults than this.