I use pfSense on a single-board computer for my VPN/routing needs but that too requires some tech knowledge.

That said, flashing something like DD-WRT or OpenWRT on a consumer router probably isn't a huge deal for most people willing to follow instructions (unless something goes wrong and bricks the router, but that has never happened in my experience). I haven't tried setting up a VPN with those, however, so I don't recall how difficult those projects make it.