The desktop OS are all pretty bad so I wouldn't want to use that as an inspiration for anything.
I mostly live in the Plasma desktop, Konsole and Firefox. And life is good.
What are you missing?
Certainly they're much more complex. More susceptible to malware, too.
But they're also much more powerful. I can get tasks done 10x as fast. They're much more open, too. They have well-defined interfaces for most things, which means I can automate tasks. Can't do that on a phone.