Also, you keep on contradicting yourself. When you say, “you shouldn’t suggest a shidduch without having any idea if it’s shayach. You’re just wasting people’s time and possibly insulting them.”, and, “unless you’ve met both the boy and the girl, however briefly, you shouldn’t be the shadchan” you are being absolute.
However, when you write, “your success rate will be very low compared to friends and family” and, “Doesn’t mean it’s the best use of shidduch energy.” you imply as I wrote, that it’s not a total waste.
I know a lot of people with successful marriages whose shadchan didn’t know both the boy and the girl, I just used myself as an example.