Also this is an awful suggestion. The reason these other services work is because of a cloud service. Rather then providing you with local control the iot devices report their state to a cloud service for wiz, Xiaomi, whatever. And you use an app on your phone or whatever which then goes through the cloud service to change the state of the devices.
This cloud service dependence is basically the reason why people come to HA. HA prioritizes direct local connection to your devices without relying a cloud service. Because it is a) much faster, b) private (since you can be certain the cloud service is aggregating and selling all data that goes through it on the side) and c) it’s lifetime isn’t subject to someone else’s bottom line (see insteon shutdown and all the refugees that created).
So no, HA should absolutely not do what you’re suggesting and become a cloud service like so many other awful iot services. If they did the existing user base would evaporate immediately, the fact that it isn’t is the reason we’re all here. Making ha work on guest networks is an awful trade for terrible performance, complete loss of privacy and the fear that it may one day vanish when someone else’s bills can’t be paid.