Recently bought a used Switch 1 as people were getting rid of them to buy the new one, but I found out that mine came with an insane amount of drifting.
Opening it up was a pain in the ass and pretty scary, but I managed to fix it by putting a card over the metal plate on the left (to apply pressure under the joystick as many people online instructed)... And it worked!
It used to drift all the way to the left whenever I let go of the analog stick, but now it snaps firmly back to the center. Just wanted to put out a PSA that if your Joycon is drifting, it's very fixable. All you need is the right screwdriver and being very careful when lifting up each piece.
This looks like a case of rubber reversion (also why old rubberised stuff on phones and such gets super sticky). What sort of temperatures were there in the TV bench? If it got hot from other equipment inside or external heat, that could significantly accelerate the damage. Either that or during the production process the rubber wasn't produced properly (chemical stabilisers not working properly, so on) which is entirely likely considering the disaster that is the Joy Con 1.
I believe it’s an original switch. Bought it quite long ago. The temps shouldn’t get very high on account of it not being in the sun and also there being no other equipment there.
They probably screwed up the rubber making then. For some reason, early Joy Con 1s in particular have even more defects than most of them, possibly due to sloppy and rushed production. It's a shame this happened though, because you should reasonably expect this to not happen on a product you buy for hundreds.