Please forgive my ignorance, but what advantage does this have over RDP/VNC?
With RDP/VNC what do you do if the machine fails to boot? Or RDP stops working for some reason and you can't SSH in?
Or for installing a headless OS on a new machine.
I'm sure there are more specific usecases as well but that's what I mainly use remote KVM devices for at home.
I’d say for many use cases, it’s not better than RDP/VNC, but if you’re looking access that is independent of the network and state of the system, JetKVM can’t be beat.
Without lights-out management, eventually physical access to power cycle will be needed.
For systems people care about, they already have BMC (Supermicro), iLO (HP), iDRAC (Dell) controllers.
Anything that can capture HDMI and spit it securely over a wire without some cloud-dependency bullshit, present "virtual USB" or input over the network, and close a RST circuit momentarily would do the job. The problem is, in the name of consumerishism and convenience, none of these home-gamer "solutions" have been independently audited that I know of by any reputable firm. (A competitor, NanoKVM, is known to be shady AF downloading serialized binary crap. It talks to tailscale without user permission, communication, or approval. Never use it for anything.) Don't trust something simply because there's press release or social media hype about it. I have to endure constant Cloudflare CAPTCHAs because it's probable that a large fraction of other customers on my ISP have pwned IoT (cameras, doorbells, whizbang startup weather station, etc.) DDoSing and hacking the rest of the world.
PSA: For the love of the sysadmin gods, please don't use desktops as servers. ECC RAM, HA, duty cycle, lights out management, and vendor support are completely different beasts compared to retail gear.
For non-lights-out, host-based remote desktop that can be self-hosted, RustDesk is able to work locally without relaying to any clouds. And using WG (non-TS) for "VPN"/remote network bridging, that's a pretty compelling option. I haven't yet checked if it can work in an air-gapped environment but I think it might work; but if it doesn't, that would be sad.
I also fundamentally disagree on your implication that one should "never" use desktops as servers, it all depends on your needs and what trade-offs make sense for your situation.
I've been doing this for decades for a basic home server (essentially, for Plex, a personal Minecraft server and a couple of other minor things for my home) in combination with a backup strategy. I guess I've been lucky that I've never had data loss, but if it packed up tomorrow taking all data with it, it wouldn't be a big deal for me.
If I had used a full server, it would have been noisier, more expensive and possibly more power hungry. The amount of money I haven't spent at this point is very substantial.