Earlier quoted context omitted.
Not sure why you're being so harshly downvoted, Chromium and derivatives have pretty solid profile switching. Doing this would actually be less work than signing out/in to other accounts.
It doesn't solve the problem I brought up - I was asking how to avoid switching profiles if I was sharing one between multiple people. GP's suggestion was to switch profiles. Suppose I and my partner want to be able to bookmark something and have it show up on both of our phones. Is there a way to do that without sharing a Gmail account? That seems like a pretty common use case to me that was pretty easy to do before…
No, my suggestion was to create separate user accounts on the shared computer for each person--i.e., each person logs in to the computer with their own user account. That would make all of the website logins separate for each user, without anyone having to switch profiles in their browser.
However, I apparently misunderstood your problem; you don't want everything separate, you just want gmail separate while still sharing Chrome profiles. You're right that my suggestion won't solve that problem.