People move a lot these days because of mainly economic circumstances that fit their age, work, family circumstances and friends are made mainly earlier in life.
Chances are thus that most friendships will be separated over time. That's not even considering relationships that start remotely in the first place.
For a childhood friendship to survive locality, their parents must not move, both you and the friend must not go to college anywhere, both you and the friend must not move anywhere else for a job, you must both live in the same part of the city and/or take jobs in the same part of the city, and for the entire duration up to the present, economic and family matters must not move both of you.
I imagine most people can list off their childhood friendships and see how each one eventually succumbs to something above. By the time you are middle-aged, your old friends (and many times family) will be split up all over the country or even the world. Most people I know that maintain a close-knit friend group are very much in the group that are born and raised in some tiny rural town and never leave or they have transitioned to long-distance e-friendships.
It's not a new phenomenon, it's been going on for generations. In my country, my generation moved more than the previous ones. Perhaps we've reached a tipping point but not anywhere near to the point that people will not move away from most of their meatspace acquaintances and friendships.
Chances are thus that most friendships will be separated over time. That's not even considering relationships that start remotely in the first place.