Never dived into it so I only came to know the hard way but that explains a ton, there's no way there will be Vita 2000 with og sticks in 10 years if it's sealed. I used mine a year and had to replace the analogs.
Discussion
To be fair, potentiometers are fine, some older equipment with them in it still great to this day, the problem is that these newer controllers and portables simply don't have good isolation and proper anti-wear prevention, it's definitely intentional, but in the Vita Slim case it could be just the fact Sony completely gave up on the thing and decided to cheap out lol