There is no wisdom in comparing WebM to flash. They couldn't be further appart in various aspects. For one, WebM is hardware accelerated whilst flash wasn't.

There's also no wisdom in Safari preventing users from viewing a widespread royalty free media format. It simply causes frustration which is evidenced by the many frustrated customers in results for "safari stream not working "webm"" search.

How do you know that the iPhone and iPad hardware have the IP core for performing hardware decoding of WebM formats? And how many such searches are actually taking place relative to the number of successful video views?

They obviously don't have the decoder because Apple didn't implement them.

I think you're ignoring other aspects of that kind of decision-making. Yes, the feature here is "power efficient, high quality mobile video streaming", but consider that content producers have to encode, store, and serve multiple different formats (plus more licensing fees for the encoders) in order to serve all their users. That's incredibly wasteful and causes people all sorts of headaches on the backend. Both Apple's stuff and WebM do indeed satisfy the user-facing feature requirements, but Apple could have just used WebM and saved content producers a lot of time and money (which often -- but admittedly not always -- translates into saving end-customers money as well).

There's of course a balance to be maintained; if we single-source our streaming video codecs, that will dampen innovation in that space. But I'd hope there's a less wasteful middle ground than the place we're at now.

HLS and H.264 are by far the most popular streaming technologies according to a 2019 survey. If anything, I’d say Apple made the smart bet, and that WebM is the real distraction for content delivery providers.

Technology license cost is not the only consideration that goes into business decisions. Consider the whole end to end process of making, distributing and consuming video, and all the parties and technology providers involved, not to mention installed bases, cost of switching, etc.