[ajarmst]

It would be less useful than you’d think. Pilots are trained to articulate what they are doing and generally follow very well-practiced procedures. Another pilot can quite accurately reproduce what a pilot is doing just from the transcript, and the warning horns and other indicators are quite expressive of other things. The audio is good enough to hear breakers opening. Anything a video camera could see out the window that would be relevant will be remarked upon by pilots.

[wizzwizz4]

In the vast, vast majority of cases, yes. However, black boxes are only used in the minority where something has gone horribly wrong.

[WalterBright]

I've watched enough Aviation Disasters to know this isn't always good enough.

[ajarmst]

Which episode has a crash that (1) they failed to find a primary cause for and (2) would have been solved had they had video?