i don’t use joy-cons since i have a switch lite, but my right joystick used to have really bad drift issues. it started just a few days after i unboxed my lite and started using it, but i didn’t return it for a new one since i thought it would resolve over time. it didn’t, and it got to the point where my right joystick was barely usable; my new horizons character was constantly walking off to the right unless i held the joystick in place, trying to sift through my storage, pockets etc was next to impossible unless i used the left joystick etc, and eventually i just stopped playing entirely since it was too frustrating.
i ended up having to send my switch lite to nintendo to have it repaired. i had to pay for it, but it was definitely worth it since i haven’t had any drifting issues since, and it was cheaper than having to buy a whole new console.