To add p338k's answer. In the settings menu for multiple users, you can also specify whether the profiles should continue to run in the background. Only then do they remain active when switching. Otherwise they will be cancelled when switching. The latter is great for saving energy for apps in profiles that are used rarely and only briefly.
@Gee: to answer your question about how much eSIM profiles are possible:
One person had written in another (German-language) Google support forum: quote: “5 eSIM profiles.”
(no guarantee from me, source reference down below…)
And also important: you can setup in the multi-user settings, that the user profiles can use phone and/or SMS.
But you cannot select a special eSIM profile for each user profile.
The second, third, fourth, fifth etc. user profile gets the connection with the current active eSIM profile last time selected in your owner profile.
The answers from the Google support forum are very contradictory and often disappointing.
There are currently more and better answers in German than in English (this may change later)
Source reference:
https://support.google.com/pixelphone/thread/181132934/wie-viele-esim-profile-kann-ich-im-pixel-6a-speichern-und-im-wechsel-nutzen?hl=de