Please.
That might result in him finishing second by team orders...
...but they probably would like to win the World Constructor's
Championship as well.
And they're not so far ahead that they need Perez to languish back in
6th place.
This has nothing to do with not threatening the "golden boy".
Verstappen is on a very short list of drivers who could be the very
best—all equipment being equal.
And I don't think that Perez makes that list, sorry.
That coupled with the fact that Verstappen seems to favour a very
extreme car setup that doesn't seem to suit Perez accounts for the
differences in their respective paces at most venues.
Put simply:
Verstappen is their number one driver.
He's number one, because he's better.
As number one, Red Bull focuses on developing a car that suits Verstappen.
Perez has to take what he gets.