There are certainly similarities. Google has built quite a moat in most of their businesses that operate like monopolies. They don't seem to be able to make a cohesive strategy for devices or services that connect these devices, but they still have massive market share.
Yes. They operate platforms with billions of users.
Indeed they do have lots of users, hence mentioning 'Microsoft in the Ballmer era' in the comment you are replying to. Lots of existing users doesn't mean a company is relevant.