Ideal vs. real.
Ideal is yes, the ball finds its way to the sand.
The real is, the more reliably you want this to happen, the steeper the face needs to be, and the steeper the face, the harder it is to keep the grass happy.
And if you instead design/build flashed faces to ensure a roll down, the more topside edging is required (PITA), and the tricker it is to ensure the right amount of sand stays in the face to avoid plugged lies and such (more raking).
In the end, I would rather be snagged in a grass face than plugged in a flashed face, and I would rather maintain grass faces than constantly raking 2 foot deep clumsy topside entry/exit footprints from Mr. Haverkamp in the flashed faces. So I favor grass faces for that reason plus the old school look.
One cool solution I've seen is to use a specific grass type just for the bunker faces. Colorado Golf Club has bluegrass rough, but their bunker faces are fine fescue. Because the leaf blades are so fine and soft, the ball most likely will roll down. Plus they are sparse and slow growing, so less flymowing, fertilizer, irrigation, edging etc. But the non "woke" crowd might not like the sparse, droughty look.