Social network Reddit recently began blocking mobile visitors to its website while pushing them to download the official Reddit app, and it's fair to say that the move is not going down well with users. If you visit reddit.com on your iPhone today, you may see a new popup that can't be dismissed, asking you to "get the app to keep using Reddit".
I don’t know of a way with Google, but with Kagi, I can block, penalize, or promote domains from my search results.