They should be wider, stupid!
Wider Rims Are the Future of Tubeless
Not sure ? Read again:
Wider-Rims-Are-Better-Pinkbike
Still not convinced ? Maybe Keith can get to you...
"The science was never difficult to figure out. Using really narrow rims and wide tyres was never a good idea. Back in the 80s we were basically riding road bikes with knobby tyres – you can save a little weight in the rim by making it really narrow, but you had to run it at 35 or 40psi. Those lightweight priorities were inherited from the road tradition. That, slowly, is vanishing."
https://www.bikeradar.com/mtb/gear/article/keith-bontrager-interview-six-things-we-learned-46802/