Because the power charging curve is non linear. You have to charge the battery slowly when it’s almost depleted or full. So they only post the numbers that make them sound best.

I’ve had a resume and a work report, both look good for me but totally broken in word.

In my experience this means that the only way to be sure that your docx document is going to look right when shared with other people is to use MS Word, thereby locking us all in.

I usually do this but would still prefer a dumb TV, mainly to reduce the possible points of failure

You don’t fund them, that’s for sure