No, I don't. Because it doesn't need to. But not running as root already provides all the protection I want. System files are not my data. My data lives in my home. I want my apps to have access to my stuff, not the whole system. But more importantly, I do want them to be able to talk to each other and effortlessly open files written by one another. "Isolating" them from each other is pointless if I then proceed to punch holes in everything just so it can work.

"This thing isn't working ... "Oh... it turns out it was missing a permission, should I give it that permission? What's it for? Fuck if I know..."

Or the other way round:

"This app seems like it's working properly, but can I restrict this particular permission for it? Fuck if I know. I'll just try and see if anything is broken"

Or I can just run the application normally and have everything always work.