There's a double edged sword here. Not even talking about DRM.
I would love to be able, myself, decide if it's fine to capture a screen for an application but I'd also would love to protect me or my non-tech-savvy relatives from accidentally share sensitive info (e.g. banking) when screen casting.
In my opinion there should be a waiver buried deep in the settings that allows me to disable such protections with a grace period of a week or so. Grace period is crucial because scammers are able to make people do virtually anything under stress and hurrying.
No, it's also iOS that's arbitrarily restricting it. I opened a bare .webm directly in Safari and got nothing on long press and nothing in any of the control widgets to save it.