Even I thought about this many times.
Logging into your device with the google account made life an easy routine. No need to remember anything. Everything from your day to day browsing history to your notes even all your personal chats are under one umbrella which you can access from anywhere provided you have internet.
As much as this has made our life easy, it has a disadvantage angle as well.
If you have logged into multiple devices and you want other people not to peep into your account, then this becomes a real problem.
Its not like at any point of time you have all your devices in your reach, and at that point how you will save yourself from the shame of the secret you have.
Also sometimes you have lost your mobile devices, then it is really a crisis.
So in those scenarios you can follow few simple steps to logout from all other devices.
Login to Google Account and Go to My Account
Select Device activity & notifications
There you can see all devices where your are logged into this google account
Click on Review Devices
Then Click on the device from which you want to remove the account
Click on Remove
