I’ve been servicing controllers for at least 25 years now. The new analog sticks they put in now are terrible. Particularly because they’re not actually analog anymore. Any dirt they pick up blocks the digital contacts and stops them from registering the stick position. That dirt gets pushed to the edges of the stick range and you end up with an outer dead zone.

WD-40 makes an electrical contact cleaner that works excellent when my Oculus controller starts drifting. Don’t even need to take it apart. Just pull the battery, spray and roll the stick around, and let it dry. It’ll be like brand new. Totally saved me from having to ship it back to the company. For Switch controllers or any controller with a battery that’s not easily removed and can’t be completely shut off, you’d need to actually take it apart to clean. I’ve seen guys do it without removing the battery, but you risk shorting them. Only one I’d be scared of is the PS5 controller. I’ve seen the breakdown on them and there’s a lot to damage accidentally in it. Otherwise, most controller breakdowns are pretty easy and can be found on youtube. Just takes the right tools, which you can get on Amazon for like $10.

Try searching for hall effect Controllers. They will be more expensive, but don’t need sliding surfaces or easily failing parts.

I use a controller with hall effect sticks for that reason. Mine was cheap and works great. Gamesir G7 SE is the one I use. I’m sure there are others out there now as there were a few being announced when I bought this one.

With the Switch controllers I found out the clicking action puts pressure on the back housing of the analog stick. Basically, the aluminum backing was bowing really bad. The best fix I found was to tape a couple layers of cardstock behind the housing so it made contact with the plastic shell. This presses the housing back into place, and also prevents it from protruding in the future.