with the shitshow that is google domains and the like, this seems like a good opportunity to look into a few of the alternatives.

I don’t see how google domains play into this? If you’re using their DNS and it sucks, just use a different DNS host instead.

most of those solutions seem built around selling seats which means they want you to add individual devices rather than just setting up a tunnel.

Are you talking about Tailscale?

The idea behind every client and server running a tailscaled isn’t to sell you more seats but rather to enable P2P connections. Their whole product is set up around this; ACLs and individual device sharing wouldn’t work without this architecture.

If you don’t care about all of that, you can simply set up a subnet router on one device and use it like a classical VPN server. Though I’ve never run into device limits on the free plan, even before they were increased.

Tailscale is as close to a hassle-free user-friendly solution as you can reasonably get.