How to stop google from using the google account in everything?

I miss the email app. Why google does not allow particular account for a particular app?

You try to login gmail, it takes the account and start to sync data of that account in all app. By the time you realize it. It has already started to mix thing and modify data of all apps.

Its good they did the thing like one account for all apps and everything, but when that account is messy and you want to start …

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