Yes, I much prefer this.
It may take some untangling things to get there, given all the history, but this makes a lot more sense to me.
I think it could be a toggle in the header. Something you can easily access anywhere.
When on, the state could be clear. We might borrow some ideas from the impersonation UX (and improve them both where needed)
I think we might want to treat some things differently.
For example, I don’t think we want to make admins toggle into admin mode to get to /admin.
Where we already have completely separate spaces for admin stuff, I think we continue to let people go there.
But for things where admins are playing in the same space as normal users, I think more explicit signaling would be helpful.