The search bar you already have is more capable than that arrangement requires you to know. With the right syntax, it becomes a precision instrument: narrow by domain, by date, by file type, by exact phrase. We can pull up archived pages, surface open file directories, and even find what people said in forums instead of what brands want us to find. None of it requires a new tool or a paid account. The capability has been there the whole time.
Advanced search operations are something Google does better than any competitor. DuckDuckGo has its bangs and I like them very much, but Google has a vast catalogue able to be searched with such precision — to a point. If you use these advanced search operators, get ready to see a lot of CAPTCHAs. Google will slow you down and may even block you temporarily if you use it too well.