They definitely are VPNs, just a specific subset of use cases of a VPN.
VPN's are usually used to create Virtual private networks. Extending your LAN across several sites using software, or granting you access to your LAN when you're not physically located close to it.
It's hard to imagine why the meaning has changed as much as it has, because even though a consequence of this connection can be that you exit to the internet via your destination networks internet connection; I feel like this isn't the original use case at all, similar to how you can use a chair as a ladder.
> encrypted proxies
I suggest "encrypted tunnels"
Because the supporting infrastructure was historically called that, and it stuck. Just like how pocket computers are called "phones" because they evolved from telephones.
Yeah, that's a really good point.
I guess at least we have the modifier "mobile" and "smart" to differentiate the different types of phone (up to and including the pocket computer).
I don't think there is a written equivalent of a VPN which is only acting as an exit node.
In fact, TOR describes an overlay network, and that's how projects like Nebula also describe their functionality. Granted, Nebula is more like a VPN than "VPN providers" also.
"VPN providers" provide a service for accessing the public internet as proxies, tunnels, etc, for evading region blocks, getting around privacy destroying things, and all that stuff. I won't knock their value. I've use them when needing internet over an open WIFI access point. I'm generally not involved in activist activities nor otherwise in harms way, so I don't have much else use of them.
But I do have use of a virtual private network. As in the core idea of it. I have a private network at home. It's not publicly available. I use Tailscale, currently, to access it when not connected directly to my home network (as in, not at home). My portable device becomes a member of a private network that has access to my private home network. This is a VPN.
I really think VPN was (incorrectly) chosen for secured proxy services because it's a simple and familiar name. The marketing using the terms "virtual private network" came far later to describe a way to secure your privacy. But it's diluted the actual technical term.