It's been a little while since I've used it, but doesn't Google let you do placement optimization based on meaningful conversions or other user-defined goals?

It's been a little while since I've used it, but doesn't Google let you do placement optimization based on meaningful conversions or other user-defined goals? It sounds like the problem here was just Google's ad placement optimization looking for CTR alone as opposed to something that means more for Aha! (e.g., clicking past the landing page). In that case, the solution isn't so much in excluding certain platforms as much as optimizing for the right goals. Unless your product/service really has no target audience among people who happen to use mobile or play games, excluding mobile/games with a blanket exclusion may be the wrong choice. Personally, I'd rather target whoever seems to be converting most in terms of things my business cares about rather than drawing arbitrary lines for which platforms see my ads.