Linux only evolved beyond a hobby project, because IBM, Oracle, Compaq, Sun decided to cut down costs on their own UNIX (thus we are back again into corporations and their relation with FOSS), and yet many still have to reverse engineer hardware capabilities despite the big names involved in it.
clang is the more recent example, it is becoming visible how it is lagging behind other compilers in C++20 support, not everything is landing upstream as it used to.
Again, though, Linux needing that stuff[1] doesn't explain why BSD happened, which needed different stuff. clang needed other stuff still. But... they all got their stuff!
It's a Jurassic Park point, really: life will find a way. Free software beat the world already, and it really strains logic to argue that that only happened because of a giant phonebook filled with special advantages for every individual piece. The much simpler theory is that it was clearly going to happen regardless.
[1] In fact that's really not the way it happened anyway. Linux on whitebox PCs was dominant in the early internet world for pure cost reasons, long before any corporate names got behind it, and that leveraged it into datacenter environments where it became clear people were willing to pay real money. Red Hat's IPO was well in the past and Google had launched on custom Linux motherboards long, long before Oracle or IBM got serious about the OS.
Dominat where? We were all using Solaris, HP-UX and Aix boxes when real money was at play.
In fact, after university during the 1990's (where we initially were on DG/UX), it was only in 2003 that I first used GNU/Linux in production as CERN was moving away from Solaris into Linux and the first alpha releases of Scientific Linux started to become available on the institut.
And even there, most researchers were moving into Windows or OS X on their local workstations.
All of the commercial Unix vendors had as their fundamental technical goal user lock-in, while Linus had technical goal of performance + stability and maybe popularity.
clang is the more recent example, it is becoming visible how it is lagging behind other compilers in C++20 support, not everything is landing upstream as it used to.