In the vast majority of cases, they have been disabled and abandoned. I suspect they leave the hatches open intentionally, since a recoverable tank means someone, maybe THEM, has to go recover it. Leaving the hatches open almost guarantees a drone will finish the job and there is nothing to recover.
“I suspect they leave the hatches open intentionally”
Very good point.
If you can get your tank destroyed while you are not in it (e.g. leave the hatches open while you sleep elsewhere), then you don’t have to be in the tank when it is destroyed.