If you are young this might not be obvious but as you get older there is nothing more certain.
Friends who you do not make the effort to see in person do not remain friends.
Staying in personal contact does not happen without action.
Facebook/text messaging alone does not count as being in contact.
Men in particular have a tendency to not maintain their friendships and many end up old and friendless.
Isn't it the thought that counts, though? Seems very shallow to maintain a "friendship" using an app.
It's weird the things that we're automating away.
Perhaps it is something best kept as a one sided thing though where only the organiser knows that they are being systematic about maintaining their friendships.
Also, when you work 60+ hours a week, have a kid, have a partner with whom to maintain a relationship, and spend an astonishing amount of time on chores, it's not shallow to just get distracted. For what it's worth, people remember, I think, just not as often as they'd like.
Even for acquaintances I see it happening. My work has two offices. Someone I spoke to a lot on Slack moved to the other office and I realized today we haven't spoken in 3 weeks. Our Slack conversations were jumpstarted by things we experienced in the flesh and they we kvetched about it all day.
3, 6, or even 12 months can easily slip by between seeing some of my best friends who live in the same region. while i'm an introvert, i deeply value the time I spend with my friends. i put a good amount of energy into balancing work and family, with whatever is leftover usually being "me time" (reading, learning, building). I try and weave "friend time" into one of the former, but it usually takes more conscious effort than i can spare.
I personally would feel like it cheapens the interaction if it was initiated solely on the fact that my friend set a reminder. I'm sure not everyone thinks that way, but why not ask?