Productivity is a lie, IMO.
Paint sprayers get paint on a house much quicker.
But you need a whole lot of masking to not overspray. Like more work than just brushing the whole house with a few drips on the ground.
And you need to back-brush anyways, for the paint to bond best.
Houses still need paint, and painters aren’t working any less with the sprayer’s advent to feed themselves.
We’re all thinking what tinkering would solve our problems, but…