I've heard that robocalls are illegal in Germany. It would be difficult to pass a law banning them in the United States because the people writing the laws are themselves heavy users of robocalls as a part of their election campaigns.
I'd just like to see phone companies made to have a free option where customers can turn off all calls from unidentifiable/withheld numbers. That would be easy to implement and stop a lot of the problem.
I think ringtones are distracting and totally unnecessary, with a few exceptions. My phone is either in my pocket, or on my desk nearby to where I'll see it ring.
I don't understand people who leave it on loud at work (or worse, leave it on loud then leave the phone at their desk). It's really inconsiderate. They are probably oblivious though, without someone mentioning it to them.