jck parent
Yep. Android does this by default, but each ssid gets a randomized MAC which persists. It is still straightforward to trigger a MAC change manually tho. It is useful for privacy but imo useless for the public wifi limits use case since they almost always require an OTP via SMS to log in.
For devices running Android 11 or higher, users can enable non-persistent MAC randomization globally for all Wi-Fi networks (that have MAC randomization enabled) through the developer options screen. The option to enable non-persistent MAC randomization for all profiles is found at Settings > Developer Options > Wi-Fi non-persistent MAC randomization.Could you describe how? Quick searching doesn't show it to be "straightforward" as far as I can find.
OTP via SMS: depends on the country. These days it's not very common in the UK. They often ask for an email address, but my experience is that most of the time they don't check it for validity.