I think it is more about the power required to run the lock motor.
I have several z-wave door locks as well. They all need battery replacement within a few months. Unless I don't open/close them very often. They can go much longer.
But it really isn't to big of a deal. Home Assistant tells me when they are getting low and I just swap the batteries in a few minutes.
I have the same lock. I didn't want it but it was the only lock I could find that would work on my sliding door.
The key is to buy rechargeable batteries. Mine last maybe a month before they need to be replaced.
Public services require a little more work, you will need to rely on a service from a company, either a tunnel (e.g. Tailscale funnel) or a VPS.
I have been hosting random public services for years publicly and it hasn't been an issue.
Edit,
I might have miss understood the definition of public. I have hosted stuff publicly, however everything was protected by a login screen. So it wasn't something a random person could make use of.
We are just stuck in our ways over here. We just got tap payments a few years ago. Even then some vendors still don't support tap to pay lol.
I always wondered why the US seems to be a hold out for adopting new technology. It might just because out government is extra slow at getting anything accomplished.
For SMS I wondered if it has something do with communicating between countries. In your experience was their extra charges involved with sending a SMS to someone in another country. (Back in the day when SMS was popular)
Here in the US we can SMS to anyone within the US for no extra charge. And we mostly talk amongst ourselves over here. So cost wise it isn't an issues. If I was talking to people outside the US there is no way I would use SMS.
After my 5 seconds of research, it seems like those SHAFT rules are more for marketing campaigns when your sending out sms messages on mass. Not for Bob and Susan talking about the latest politics. Not sure why OP is getting limited.
I can swear over my Google Voice message and I don't have any issues. I am pretty sure that is SMS over VIOP.
That has been a thing forever. I doubt it will ever go away.