that happened after nadella changed course from the balmer years. It is not always the case that a new CEO can turn around the company (for example see GE).
See also SUNW. McNealy imported the 6Sigma thing from GE, at one time it infected even teams not involved in manufacturing. MSFT had the best outcome for giants of the aughts. It is too bad OpenSolaris was left for dead, otherwise we'd have some choices and competition in *nix OS. AIX, dead. HP-UX, dead. Can't recall the DEC, Ultrix? Who runs that anymore. The last time I saw BSD commercially used was at a telco.
A lot of my early jobs were porting various Unix things to Linux. I spent time writing cross platform C++, perl, and bash on Solaris, IRIX, HP-UNIX, and DEC Tru46, but mostly Solaris and IRIX.
I gotta say, all those Unices fucking sucked. The userland tools were abysmal, with missing flags or bugs in their getopts, the compilers and their sockets libraries were extremely finicky, and their man pages were anemic.
GNU/Linux won because if something sucked, somebody somewhere would fix it. By the early 2000s, and especially after Linux 2.6, it was obvious closed-source UNIX was both worse and overpriced.
Even now it seems like the best part of the closed source MacOS Unix stack is the open source homebrew/macports stuff.
Agree with you that tooling was abysmal but all of those *nix had their bright flowering that subsequently pollinated other *nixes. AIX service management (SRC I think?) eventually saw life in Solaris as SMF. BSD jails reborn as containers. The HP-UX had batch job management that was very good. Solaris ABI/API compat between versions was exemplary, you can count on the OS upgrade not breaking your application. When the compiler was still being sold (thousands of dollars by the seat license), it was optimized for the SPARC processor and outperformed same code compiled by the GNU compiler. I wish we had all of that still.
Apropos of the "curated App Store" or "free-for-all" discussion currently active, I remember talking to a colleague in the early 2000s that Apple with its curated BSD-derivative OS was exactly what open sourced OSes needed. Users don't want to do more work than necessary; in retrospect, the selling point that users can do anything+everything with *nix OS was the wrong message.
You didn't mention package management and network booting to be pain points. They were nightmares, which Linux eventually solved. I think that's where the race was lost.