Honestly, people committed to plans in a way they don’t now. I rarely had last minute cancellations when I was younger. Time might have been cut short or something, but people showed up. Changes of plans happened well in advance. Occasionally, I got stood up, but it was rare.
Now, I’d say probably 20-30% of the time, plans get changed last minute or more rarely, somebody bails.
Otherwise, yeah, having a mobile computer/phone in my pocket is indispensable and I’d never fully give it up.