Amazon and Alibaba are pure consumer plays with a mass audience. They deliberately hide the contact forms to force you through self-service UIs.
If you try the same thing with a B2B or other high-touch service, it's not going to end well for you.
Personally I get a terrific amount of value from interacting with my B2B customers through chats, video calls, and screenshares. The customers love it.
My experience with this kind of services has always been lame and I strongly believe only bad businesses use them
For example the two larger e-commerce sites in the world,Amazon and Alibaba don't use them
If they were a major improvement, they would.