Is Apple taking steps to purposefully blocking open stuff, or are they just pointedly ignoring it and continuing to develop new hardware? I am genuinely asking, I don't know myself.
edit: speaking mostly about macOS here, mobile OSes are much more locked down
The fact that they still allow this would point towards the latter. They are quite capable of locking it down like they do the iPhones.
It’s the latter
For desktops and laptops, the latter. But for phones and tablets they do not want user control. And even where they do allow it, even a tiny effort in hardware documentation that would make it so much easier never happens. So it's quite hostile overall.