Trust was eroded because every year they came out with some improvement on it that was supposed to fix the problem, then at the end of the year models with those keyboards were added to the expanded warranty program.
I think it would have been better if they had a real fix for this issue, it probably would have been expensive for them with a redesigned top and bottom case to fit a decent keyboard but right now the butterfly keyboards seem like ticking time bombs. Eventually they will die and Apple will either ask several hundred to repair it or say parts no longer exist and buy a new one.
1 Admit the issue before a class action lawsuit is running
2 Put immediately a statement that there "could" be an issue and it is investigated. Apple kept their mouth shut and the fanboys attacked the people that reported the issues that they use the keyboard wrong or some even claim that is is an anti-Apple conspiracy.
Maybe Apple should have just swallowed their pride and addressed it in a single product cycle. I was one of the people waiting for the keyboard to be fixed before buying a Mac, and I just ended up switching to Linux before it happened. I ended up buying an M1 Macbook Air, but it doesn't get much use these days besides multiplatform testing.
But Apple have always been good about free, no-questions-asked, out of warranty replacements for faulty/sticky butterfly keyboards. Not really sure what more you could reasonably want them to do.