Why does my 9th gen iPad battery die so fast?

This is why their removing battery health and date of manufacture is frustrating because all you have is their word that it's working as expected. The previous response from the community specialist is not related. For example, if I launch netflix and watch video constantly, the app that's using 99% of the battery, according to that screen, is Netflix. After 3 or 4 hours of netflix, it's done. On my 6 year old iPaid Air 2, I'm getting 8 hours with a really really old battery.

Given the battery tests performed on youtube with the 9th gen and other iPads, it should have easily gone 10 hours watching Netflix or any other streaming service. I conclude, therefore, that the battery is defective either due to manufacturing or because it sat on shelf dead too long. It came completely discharged which tells that it sat on the shelf for at least 6 months.

I returned it to Amazon. I'm going to wait until the regular iPad has USB-C so it doesn't take 12 hours to charge.

Not even remotely related to the question.

My only suggestion is to be the squeaky wheel and try the Genius bar again. Rather than straight up having them test it, challenge them to streaming the same app an content on a 9th gen they have there side by side with yours. Should be obvious pretty quickly when your battery percent drops a lot faster.

What's sad is that my 9th gen would get really hot while streaming Netflix or Prime while on my 6 year old iPad Air 2, it stays cool the entire time. This is with displays at the same brightness.