For some of them, they do. But they could have implemented some of them behind a feature flag/cli flag or so? They did this for things that were bigger security headaches. That way they'd collect all the real world issues and iterate on their solutions for their privacy concerns. Right now, it is just one more reason why Chrome taking over their market share.

It is not like the use cases for connecting devices and use them via. the Web Platform will suddenly disappear if they don't support it.

Their reasons to push against WebUSB are, imo, valid. There are legitimate concerns and a high level of complexity to allow such low level USB access in the web browser.

Their reasons to push against WebSerial are not as valid and that would still cover most use cases without the downsides and complexity of the full WebUSB.