[link|https://www.ifixit.com/Guide/How+to+Fix+Left+Joystick+Drift+on+a+DualShock+PS4+Controller+Without+Soldering/140074|This guide|new_window=true] works pretty well for fixing drift
If it doesn't fix it, try sending it to Sony for repair, they are usually good with that kind of thing.
Did you trying replacing the joysticks?
That usually works for me.
If it doesn't fix it, try sending it to Sony for repair, they are usually good with that kind of thing.