To put it another way, consider if you have a significant other (where you share bank accounts, for example):

Are you uncomfortable without your phone even if they have theirs?

I’ve been in this situation and it’s not a problem at all. In some situations, it may be an inconvenience, but I wouldn’t call it “uncomfortable”.

But with my SO having her phone, we have all emergency situations covered (directions, contacting others, money, etc.), and that doesn’t — and _shouldn’t_ — bother me.