I agree. I think the lack of new operating systems since late-90s can be (partially) attributed to the simple fact that modern computing world is so fully-deve

I agree. I think the lack of new operating systems since late-90s can be (partially) attributed to the simple fact that modern computing world is so fully-developed, we have the computers for everything, and enjoy all the state-of-art features and functionalities. You already have, well, all the things you have on your personal computer. Although desktop apps are getting crappier and crappier as always (which is another story), but some parts of underlying infrastructure are created and only understood by the best developers in the world (high-performance TCP stack, 802.11n, multimedia, 3D graphics, TLSv1.3, PCI-e, USB 3.0, virtualization, exploit mitigation, web browser engines, C10K-free web server). By creating a new system, you lost everything immediately and render the computer less useful, making it less attractive for both hackers and academic/industrial researchers alike. Back in the early days, not too many things were being done on computers, and you had fewer things to lose. Want to play Space War on PDP-7, but don't even have an OS? Then Unix! Want to do some real work on 80s home computers? BASIC! Micro-Soft! When Linus purchased his computer, he found that the computer only runs DOS and was effectively useless for him. So he ordered a copy of Minix, meanwhile playing a DOS game to kill his time. After Minix arrived he eventually got a usable programming environment, was able to got online to Usenet with a modem, and also got the Minix filesystem which was suffering from performance issues at that time. This is everything he had for his computing. Then he decided to create his own operating system. He wrote the kernel, ported glibc, bash, gcc, and the system boots, later he added modem support. Now he could do everything he was able to do on Minix. That's it! Naturally, a few years later, it became a community project and gained huge momentum. Perhaps the early-90s was the last era, when hackers can "just" create a operating system in a tinker's way. On the other hand, new OS are still being constantly created on platforms which don't have the burdens of workstations/servers, we still see many hobbyist/research/practical systems on microcontrollers every year. As they became more and more powerful, then it also runs Linux and the story ends there... I think this is also one reason that retrocomputing is getting more and more popular, it brings back the "playground" nature of early computer systems, unlike the "factory" nature of modern ones.