Technically speaking it does nothing of the sort. It helps websites be absorbed by Google so that Google can retain the user on their site. Which keeps the experience fast. But you don’t need Google to make your site fast, and in some cases using AMP can slow your site down. If it was just about making the web fast, there wouldn’t be AMP-only features. It would just be “fast only” and websites would have to meet certain criteria to pass that test. You should try using your brain a little more when you think about the motivation behind Google’s actions. Do you think the stakeholders at Google care how fast a user can exit Google?