Removing Flash, Mutation Events, and third-party cookies broke websites.
Flash was a third party plugin that got way out of hand. It wasn’t (necessarily) the job the browser vendors created for themselves and offered for years.
Flash was also moreso removed on a fledgling platform first that grew to be a dominant platform; it wasn’t killed off on an existing dominant platform first.
I called out Flash. I could not have written a more straightforward note about how their comment was set up. Nothing I said indicated I disagree with their overall stance, just that Flash is a ridiculous thing to trot out.