Apple recently quoted me 2,300$ to fix just one broken keyboard key (it was M, if you were wondering), because according to them the water sensors were tripped and it's policy to replace the mtherboard if that happens. Which apparently costs more than buying another two working identical MacBook Pros.
The laptop has never gotten wet, and everything apart from the M key was working perfectly.
Do you live in a hot, humid climate? I think a lot of those water alarm stickers show false positives if people move from a cold, air conditioned place to the humid outdoors. Condensation is unavoidable unless you wrap the laptop in fairly airtight bag every time you go out.
I am certain that many people have been denied warranty claims because they live in cold climates and visit indoor swimming pools regularly (coaches/lifeguards/spectators etc). The condensation in that situation is impressive.
It's okay, we did the same thing for warranty claims when I worked CS and Tech Support for one of the major phone carriers a decade ago. If the LDI was tripped we wouldn't replace it under warranty, and I'm sure there was more than one warranty replacement I rejected that was a false trip instead of actual liquid damage (a better indicator for this is corrosion on solder joints than those stupid stickers).
My fiance had a similar experience with actual liquid damage. I've forgotten the details, but she spilled a tiny bit of a drink into her M1 MBP keyboard, taking out most of the lower half of the keyboard. Apple wanted roughly the cost of a new M1 MBP to fix it. She ended up just getting a BT keyboard..
The laptop has never gotten wet, and everything apart from the M key was working perfectly.