[tomschlick]

If it's openvpn you can just port forward from your router to the RaspberryPi's internal ip address.

If it's a webserver you can do the same, or use something like Cloudflare tunnels to expose the service.

[duskwuff]

Or, like the original post said, use Tailscale, which can punch a hole through the NAT for you.

[Aachen]

Port forwarding is easy and self-reliant compared to using a third party's free service though

Not saying that's for everyone but I do feel like the default should be to click the two buttons in your router interface and third parties a fallback option or conscious choice. Probably just as quick as signing up for tailscale, if it weren't for that all routers feel like they need to reinvent a UI so it's never twice the same

[jeroenhd]

Not everyone can get port forwarding, though. If you're stuck behind one of those terrible CGNAT+no IPv6 ISPs, you can't host your own services from home that easily. There are more of those shit tier internet providers out there than you'd hope or expect.