When you agree to meet someone somewhere at some time, all further communication is redundant (I expect you to be reasonably punctual and I don't need your SMS updates "Hi, leaving the house now." followed by "hi, I'm running 5 min late", I will wait, and if you are not coming, you can call me to apologize if you care one bit).
For people who don't know their way, you can use in-car navigation systems rather than smartphone map apps.
99.9%? I am old enough to remember time before mobile phones, and being at a place at a prearranged time is possible. Also, if you are late, you can actually do a phone call to inform the other party - all you need is a feature phone, not smart phone.
I personally respect other peoples time and I expect the same for me. That is, I have cut out people from my life in the past that repeatedly would text "hey I'm 20mins late" 2mins before the agreed time. That is still disrespectful with my time, because now I know you are late, but still lost those 20mins. Some people don't consider that rude and for some reason do not see that this would not work if everybody does it. Needless to say, my friends know that I value reliability, and most of them do. People that don't respect that don't need to be in my social group, or at least I don't make plans with them.
Norms describe averages, I do not necessarily have to follow them as an individual. Eating meat is a social norm, yet in my social group there is far-than average vegetarians and vegans. This is fine, and I don't see a need to change. I as an individual can decide with what other individuals I want to surround myself. And I chose not to surround myself with people that are always late and unreliable.
Let us use Constructivism. Countries do not drop nukes on each other. However, if one starts, everyone will follow. Or you may have an arms race situation, one country gets colonies and unless you want to be dominated by other countries, they also get colonies.
No phone number? Spend more time getting services. Unable to get services from some companies. Miscommunication/frustration. Less connections/acquaintances.
Maybe this ends up working for you, but it lowers your 'power', the ability to get what you want. I do have concerns that it works in the short term, not long term.
"Getting what you want" is not an attainable life goal for me. People who do that above all else, are willing to throw away with their values whenever it benefits them. So you end up not having or at least living by your values. Unless your value is you above everyone else - Exactly the people I avoid. And why would you want to surround yourself with people that only do what benefits THEM?
Still 30s, but also I make new friends all the time from 20s to 70s by just trying to say yes to go new places and hang out with new people. Board game nights, concerts, bars, video game nights, hackerspace events, movie nights, puzzle parties, and hosting events myself.
All sorts of places to make friends at any age once one is willing to put a phone down long enough to say hi to someone new!
For people who don't know their way, you can use in-car navigation systems rather than smartphone map apps.