You're right, it does make sense. This is how the internet was designed but not how it was implemented.
Originally, every machine was a directly reachable peer, but a finite supply of addresses (IPv4) forced most devices behind translation boxes (NAT) that let them dial out without ever being dialable. Once traffic had to route through the few hosts that stayed reachable, those hosts became toll booths, which is partially where the more centralized internet we actually got came from.
HomeAssistant is probably doing too much for what you need. Imo it's not a good piece of software. https://nodered.org/ is maybe a better fit. Or just some plain old scripts.
Originally, every machine was a directly reachable peer, but a finite supply of addresses (IPv4) forced most devices behind translation boxes (NAT) that let them dial out without ever being dialable. Once traffic had to route through the few hosts that stayed reachable, those hosts became toll booths, which is partially where the more centralized internet we actually got came from.
iroh basically patches the internet