graphire Is there a way to prevent this from happening after I factory reset my phone and start using it again?
I wish I could give you a confident answer.
I think the Pixel 9 series has working "Device diagnostics" in Settings? I have a 6a, and I don't think the indication the 6a gives for storage health is meaningful, but you if you get there eventually you might check to see if maybe your device has a negative opinion of its storage.
If a little bit of the flash storage went bad, and the storage controller plans to map that part out, and it was a one-time random event not part of a trend, then if a "factory reset" completes successfully the device could be fine indefinitely going forward.
If a lot of the flash storage went bad, but it can be mapped out, then it's possible that a "factory reset" might cause the device to work ok for days or weeks but then it might go bad again.
If the flash storage is fine and the problem is file-system corruption, the best advice I know of would be to avoid running the battery all the way flat, because there is some reason to suspect that maybe that's a problem. But I would expect that to lead to a boot loop without tripping the dm-verity "corrupted" alert.
Somebody else may have advice, but for at least the next few days I think the developers are working very hard on A16 QPR1 and then Pixel 10 support. And I don't think there's any way at present to get solid diagnostic information from the device.