I was able to use Google fine for many years before it was banned. It can get banned when you search for certain keywords, not arbitrary at all.

Google was about the only one I can think of that is not worse than their competitors, and their own product actually don't need much localization.

However, Google failed the growth part in China. Chinese users won't go ahead and set the default search engine to google.com on their own unless they already know about it, especially those don't know English. The homepage used by most Chinese are local websites like hao123 that would send traffic to Baidu

google.cn is located at its Beijing datacenter. If it's multiple times slower then Google's network optimization was really shit. GFW only works for cross-border connections.