As LuganoPirate princely noted above, unless you make initial contact or invest time in keeping relationship going, in majority of cases none cares. There are exceptions ofc.
People are the same everywhere. If you trying to argue Swiss are special, you are just fooling yourself and/or have negligible dataset.
Talking about British and Swiss friends actually. People are NOT all the same, irrespective of country of birth or abode.
Many of my Swiss friends were friends in the 50s and 60s - and are still friends even though I lived a long way away for all my adult life. Many of them also lived all over the world ...others have never travelled at all.
its a myth and all case by case
if you dont invest time into friendship it will fall apart. older people tend to invest more as they are not distracted by online garbage like facebook or instagram. younger people are not.
thats natural, part of life evolution. we will come to something else.
In all my 40 plus years of working I've only every kept in touch with one colleague, and he was someone I met back in 1997 when I worked in a London gallery. I don't see it as being a big deal tbh. However, by comparison my retired sister keeps in contact with just about everyone, including people she worked with in the Middle East.