'We all do' is correct and can be used in written English. You could use it to emphasize that everyone agrees with a particular sentiment or action. For example: "We should all spend at least 30 minutes outdoors each day - we all do."
We all do it [norms].
Like we all do.
We all do.
Maybe we all do.
We all do dopey things.
We all do our thing.
I love the desktop app, it’s always running on my Mac. Ludwig is the best English buddy, it answers my 100 queries per day and stays cool.
Cristina Valenza
Retail Lead Linguist @ Apple Inc.