Again, if scraping data from websites without permission, Google simply wouldn't exist. Bear in mind, robots.txt is a feature that Google and Microsoft choose to respect, but the default assumption search engines have made from the beginning, is that they are free to grab whatever they want from the web, unless you ask them otherwise to please not.
Which Google's robots.txt does.
> scraping search results isn't illegal, by any means
While scraping the results for yourself to look at might be OK, scraping results to display verbatim in another search engine without permission stretches fair use.
No, it doesn't, because Google results aren't copyrightable, hence, there is no such thing as fair use. It's just information anyone is free to collect and use as they see fit.
If a monkey can't copyright a selfie because they're not a person, an algorithmically generated spew of stuff Google ripped from elsewhere certainly lacks merit for copyright.
Google Search results are definitely "public data" so long as Google provides them to anyone who asks.