[stevage]

>Changing up the terms minimizes the very shared experience your friendship was built on

Yes, and that's when you find out whether the friendship was merely "built on" that experience, or is entirely composed of it.

I have lots of friendships that were formed in the kinds of experiences you describe - especially long distance cycling. Those people all have kids now, and we don't go cycle touring together. But I put the effort into finding other stuff to do with them, so we're still friends.

[bossyTeacher]

I think it really depends. If you decide to smoke weed 24/7, I can choose not to be around you because I dislike drugs. Doesn't mean I was your friend before. You can replace "smoke weed" with joining a religious group (be it scientology, yehova witnesses etc), becoming a hiking junkie, only having a nighttime social life, joining a street gang, skating 24/7, going off-grid or some other time consuming thing that expects the other party to make things they might not want to do to be with you.

I became friends with you. If you change yourself by making a choice (whatever choice that might be), you shouldn't expect the other person to still stick with you.

[stevage]

I'm not quite sure what your point is. You can end a friendship with anyone for any reason. It usually takes more effort to keep it going than to end it.