Qubes has an excellent security model and should a top choice (if not _the_ top choice) for security-minded and technologically sophisticated users.

I used Qubes for a year or two, and then realized that my main use case was to isolated the browser, which to me was the greatest threat vector compared to everything else I use. Then I thought, if I just wanted a system with the browser isolated from my main Linux environment, wasn't that exactly what ChromeOS provided?

So I switched to ChromeOS and have stayed on it ever since.