When did Google ever start forcing users to sign up just to search?
If you visit the Google search engine, it will set a tracking cookie that is used to serve ads to you, so they are forcing you to sign up to their targeted ad service to use their search. If you want to be able to configure the search settings, then they do this via the tracking cookie. This is not a technical decision: DuckDuckGo, for example, sets a cookie that just has a set of preference flags in it, so any two people with the same preferences will have the same cookie, not a unique identifier, and the web server can handle these preferences without needing any kind of database lookup.
I'm not sure if the EU is aware, but Google is absurdly popular. I'd be shocked if Gmail didn't come up #1 in a search for email
That's certainly true now. But when gmail launched, it wasn't absurdly popular, it was a new contender in an established market, yet it still showed up at the top of the search results.