I've used mine as a bridge to my home network if I want to access it from work. Use my phone as a hotspot, wireguard VPN from my phone to home network, then connect my work laptop to my phone's hotspot.

I already use cloudflared to expose a couple of hosted services that I commonly access remotely, but it's nice to know I can use my phone/VPN as a quick way to get to my entire home network from any computer, without the network being publicly exposed 99.9% of the time

That's true, but most of my social group fits into this definition and the majority fly commercial 6 - 12+ times a year, all around the globe, either for vacation or business travel. They almost all own personal vehicles, replaced every 5 - 10 years, well before the end of life of the vehicle. I live in Colorado and it's common for this class to own/rent a second home or condo in the mountains and take multi-hour drives to those places on the weekend. Those lifestyle choices produce massive amounts of CO2 relative to individuals who otherwise live generally identical lives.

It doesn't take extravagances like private jets to contribute outsized emissions.

I VPN to my pfsense firewall and there are a bunch of guides about how to set up OpenVPN or WireGuard for pfsense. Ultimately, it's going to be dependent on the configuration of your home network - you can set up a VPN tunnel to your router if it supports that feature, or you can use an always-on device on your network to serve as a VPN server. Happy to give tips to point you in the right direction, depending on what hardware you're running!

I guess you're kind of right, in that they're both essentially 0. But the odds of winning the lottery are still ...millions? of times higher to win by buying one than finding a winning ticket on the street.

/pedantry