Some of the listed evils include mass surveillance, mass censorship, participation in drone killings, stealing and exploiting people's data for profit, building murder robots, colonizing physical space, systematic tax evasion, law violation, corrupt political lobbying, so on and so forth.
To your point, measuring the evilness of something is going to be fraught, especially in a competitive space of a bunch of other seemingly equally evil entities like Amazon, Facebook, etc.
One of the interesting differences is your other point, the "better alternative." Alternative to what? https://wiki.fuckoffgoogle.de/index.php?title=GoogleAlternat... - their reach is so far and wide that it takes pages to list out alternatives for the bits and pieces of what we use Google software for now. "BETTER" is relative and difficult to define, especially when one of the major advantages to Google products is their ubiquity.
"What is evil anyway..." great question. At some point, it seems like you know it when you see it.