There's a difference between not being designed for something, and being designed to prevent something.
HLS isn't designed to prevent saving, it's just optimised for streaming.
Re:How Video Streaming Processing Works
by danachow on Tuesday January 04, 2022 @01:38PM
(#29798286)
The GP stated that hls makes it harder to download and store videos which is mostly a dubious claim, but even if it were true, in most cases where it’s used this is (if only hypothetically) a benefit since major stream providers generally don’t want their streams stored. The reply sounds appropriate.
And all of the studios cheered! /s
But in reality, it hasn't, right? There are so many tools available that will download a video as a single file for you that's not even an issue. You should try looking for the Wizard with that strawman.