I’ve only used VPNs on dedicated hardware like Sonicwall or Meraki and someone else always did the initial setup. So feel free to laugh but I’m wondering: with a VPN like Wireguard, is it normal/common/standard/preferred/[insert other adjective here] to use a dedicated device for that purpose or just tack it on to a current server?
Scenario: This is for home personal use and my current server has Nextcloud, Riot, and similar services running.
As answerd before it’s totally fine to do that.Since we we’re going to work from home due to the corona crisis I took a RaspberryPi 4 that was collecting dust and installed WG on that. We are ~8persons connecting to that server for 8 hours every day without any issues and we are maxing out our offices connection at ~500mbit without any issues.
I run a couple of WG instances at home.
My main router is a VyOS VM in a Proxmox host. I run my personal WG on it to connect to my VPS, and several external devices (phones/tablets/etc).
For work, I stood up a VyOS VM on my VMWare cluster at the datacenter, and we use EdgeRouter-Xs as site-to-site devices (running WG) for select staff (mostly IT for now). Since I already have a Proxmox host at home, I decided to run a dedicated VyOS VM at home just for my work VPN (and opted not to use the ERX), so I could keep my personal traffic personal, and everything behind the work VPN is work.
I would have no problems running a dedicated device for this purpose. In some situations, I feel it’s appropriate.
Or even openwrt - wg doesn’t need a lot of CPU oomph compared to OpenVPN for example, so you may be surprised at throughput on a discarded wifi router if you have one lying around that can take OpenWRT.
https://openwrt.org/toh/start search through that for your discarded devices and look for a compatible one. Then check the device page itself though once you find one you own - some devices can be easily flashed from the stock web interface, other need TTL serial, JTAG or a tftp server, to varying degrees of “it’s too hard” for a first-time OpenWRT user.
The advantage of using an unused AP or router is low power (and therfore heat), space, the use of spare ports as a switch and possibly extra wifi. Cost (zero if lying aorund doing nothing) is a minor factor in my experience.
Tip: don;t bother with anything that requires a custom build and aim for a minimum of 8MB flash, 64MB RAM even for a experimental test. Fine for playing with OpenWRT for a first install and maybe light-use wg too but better to have 16MB flash and 128MB RAM for future versions of OpenWRT.
To my slight dismay the size of the default mainstream install of OpenWRT is now 8MB ROM/64MB RAM. Dismay because I have access to hundreds of 4/32 devices at my emploi that just cry out for OpenWRT to fix their stock firmware problems. (yes, I know i can build compact images with no GUI, but noone will pay me time for it)
And yes, Raspberry Pi wg instances are very popular, especially when combined with things like pihole or MQTT/smart home packages.
You definitely don’t need beefy 19" rackmount servers with multi-processors and banks of RAM 
a 400MHz single core and 64MB RAM is a workable wg solution for anyone on ADSL or slower VDSL on OpenWRT in many cases.
Don’t go crazy or spend beer money. The world is in a crisis. Beer is a vital resource so use it wisely.
Thanks for the concise answer.
You preemptively answered my follow up question too!
Thanks for the input, especially the beer money advice.