A big component of the principal agent problem is a timeline mismatch.
If you have a principal agent problem: people who are not on board for the long term will choose the minor short term benefit at catastrophic long term cost.
Imagine a world where you were locked to a specific collective, for live, with no possibility for exit.
We only care about things on the time horizon we expect to be involved.
Renter mindset vs owner mindset.
The reason no country allows tourists to vote is because if you had only short-term users voting, the country would be destroyed.
So why doesn't that happen to public companies, which have a large number of "tourist" shareholders?
The reason everything isn't destroyed immediately in practice is because there's a mix of short- and long-term interest.
Imagine that every single shareholder was expecting to hold the stock for precisely three months and then sell it and never hold it again.