>I don't see any significant barriers keeping a user from switching to a competing product.

This is the difference, or the similarity however you look at it, between Google and Microsoft. You claim that the barriers Microsoft put up to prevent users from switching were significant, but Google's aren't. I disagree. In the literal sense no one was locked in with Windows and users were free to install other browsers or even switch to Linux or Mac.

The complaint was that Microsoft was making it difficult for the average user to do so. That's the same complaint these companies have about Google. For you it might be an easy task to download your data from Gmail or Chrome but I'm sure for the majority of users switching search engines is just as obscure as switching browsers.