Many users own two Google Accounts, for instance:
- Business (Work)
For example, they don’t want or cant use their work Google Account to access Youtube and they want to use for YouTube only their personal Google Account.
Multi User Access (MUA) Feature designed exactly to solve this issue and many others,
Allow the end-user predefine which websites/services will use which one of his Google accounts.
So the user can predfine Gmail will be always using the work account and YT always using the personal account and Calendar always the Work account. Would save lots of time as well for the users with few Google Accounts due to this reason above.
Hope it helps!