Only took 5 years, but looks like they are starting to push this. Can enable it in Set Preferences.

I can't see myself using it until you can customize the colors. I don't trust myself to not screw up something thinking I'm in Sandbox otherwise.

Some pages are just difficult to use. like an revenue arrangement. just looks like a wall of text with no sublist borders and such. I turned it off after 10 mins.

I like it for the dashboard - but have turned it back off / don't like the no borders on forms etc - I think maybe just too used to looking at them all these years 🤣