It's not in the slightest. It would just be a sensible design decision (I say "would be" because I don't use YouTube annotation nowadays anyway; my captions are hard-wired). For people who don't care to use your product correctly, "all bets are off" so to speak. And just on a practical front, it's not even clear to me that you could compensate for people who leave the intended annotation off, even if you were willing to compromise your video and spend extra time in an effort to do so. It's not necessarily going to be easy to convey certain things in the imagery alone.

: TBH, if a person is creating gameplay videos, it is unlikely that that their
: 'artistic vision' is superior or even well considered. And they would do
: well to take a few lessons from those that have been making videos for
: decades. To make a video that is just BETTER - not to pander to anyone.

: There are such things as short films, music videos, commercials,
: instructional videos which are more similar in length or content. There is
: a lot of crossover in the realm of 'good practice' even if you don't
: consciously realise it.

You're going off too far with that. I wasn't saying TV/film practices don't apply; more that they shouldn't all be taken as givens (or have the same level of importance) for gameplay videos. In the case of that 'rule' about getting attention at the start for example, I'm under no pressure to maximize viewing figures, so I needn't feel so constrained by that way of structuring things.