Is the verb 'get' a really cuasative verb?
There's an explanation that the causative get means convincing 'someone else' to do something, and I know there's the case as "I got my hair cut", but lately I've been seeing the opposite cases a lot, such as...

"Let's get this done together"
"The authority was the one that got it approved"

or maybe this example will do?
"You are the one who got it approved"
Here, 'you' is a someone in charge, and 'it' is a form of document stamped by 'you'.

Those kind of sentences have the same structures as in the causative get's cases, "get something PP", but imply that the speaker or the subject, not someone else, are the ones who do the actal stuff. What am I missing here?

Question

Is the verb 'get' a really cuasative verb?
There's an explanation that the causative get means convincing 'someone else' to do something, and I know there's the case as "I got my hair cut", but lately I've been seeing the opposite cases a lot, such as...

"Let's get this done together"
"The authority was the one that got it approved"

or maybe this example will do?
"You are the one who got it approved"
Here, 'you' is a someone in charge, and 'it' is a form of document stamped by 'you'.

Those kind of sentences have the same structures as in the causative get's cases, "get something PP", but imply that the speaker or the subject, not someone else, are the ones who do the actal stuff. What am I missing here?

Answer

"To get" has many, many different meanings.  I counted 27 meanings in the first dictionary I checked.

It can mean "to do," "to encourage someone to do," and "to force someone to do."

Here is more information.
https://www.espressoenglish.net/causative-verbs-in-english-let-make-have-get-help/