This is ridiculous. Apple’s (nor any multi billion dollar company’s) QC wouldn’t have ok’d a device that requires cleaning every day to prevent its main selling point from working properly.
Many are saying the blu-tak method hasn’t made a difference, so it’s not the common cause everyone is hoping for.
Apple released a phone with an antenna design that wouldn't work if you covered it with your hand, so don't be so sure that real-world use wouldn't reveal something they didn't consider. Samsung released a folding phone without realizing that people might try to peel off the non-removable protective layer on the screen. These things happen.
The AirPods Pro DEFINITELY need regular cleaning to work 100% as intended, depending on your personal genetics and amount of ear oil secretions, etc. It's objectively true that the fit test will eventually fail if the vent gets plugged with ear oil/wax, or other contaminants, and the sound quality will degrade as well.
If the blu-tak method doesn't work, there are really only a couple possibilities.
A) Blu-tak method often requires a firm, consistent cleaning for best results. If you don't take the time to do it properly, then it might not have the intended effect.
B) Or one of the MEMS microphones has broken, resulting in poor performance.
And the firmware thing is kind of bizarre if you think about it, because all Apple would have to do is increment the firmware one step and re-release the old version. Easy. Why in the world would they make users sit on a firmware update that breaks anything, if they could roll it back just as easily?