Are you saying that S&W, FN, Glock, etc didn't do their research when they started producing milled slides instead of just making dovetail adapter mounts
I already told you the milled slide is "better" because it gets the dot lower -- if you go with really tall sights you can even co-witness with the irons if you don't care about the possibility of a tall front sight snagging on the draw.
The rear sight replacing mounting plates are a perfectly adequate 3-rd party solution, as is sending off the slide to be milled to mount an optic.
S&W, FN, Glock, etc. are followers, not leaders in doing this, but overall it should be more economical to have slides milled by the maker initially instead of by an independent gunsmith later. I'd be thrilled for this to become a "standard" feature. Some of the lower profile advantage is lost because they seem to be using an "intermediate" plate to account for the different mounting screw patterns among the red dot brands.
But real innovation here would be integrating the design of something like the Trijicon dual illumination RMR sight into the slide design instead of just making provision to bolt it on afterwards. This could result in an even lower profile.
Sometimes there is not enough "meat" (or width) in the slide for a direct milled mount, so the dovetail adapter plate is your only choice.
Works for me, approaching 5K rounds through it, I trust batteries a lot less than the dovetail mount so I went with the dual illumination RMR:
