You can't get the PS5 or Series X easily, you can with a Switch, if there was a lot more stock of the other two do you think Switch would've held them off?
PS4 didn't sell (ship) its highest until the 4th FY (I don't have UK sales), popular things sell lots and the Switch is very popular.
I don't have a Switch, almost dipped but stopped myself last minute about a year ago.