Ask HN: What does a new operating system look like in 2023?

It feels like every platform shift we see a new operating system for that environment. Desktop, Web, Mobile, ... In the case of web the operating system is essentially the browser. Mobile was a massive undertaking with the hardware shift but it doesn't feel like we've seen anything similar for the Cloud. I'm just wondering after seeing a number of new browsers show up. Is this a second shot at an operating system that's truly open? If a new OS was to be built today what would it look like? Would we build everything from the ground up for a cloud based environment?