All of Google myriad of properties benefit from being able to limit competitors web page size, limit their technology use, restrict advertising and gating them behind your own servers.
Plus on top, Google doesn't have to do any of that shit themselves and can gleefully put themselves at the top of every search (and are doing with an ever expanding array of search terms).
As well as increasing the cost of developing a site to compete with any of Google's myriad properties, by having to support HTML and Google's proprietary AMP, that they're pretending is an open standard but is completely under their control.
Why shouldn't a company be able to decide what they feature on their search results and how they rank things? If every result was a Google owned site, so what? Nothing is stopping you from using a different search engine.
Hence the big fines that google is starting to get hit with, with some regularity.
AMP links are everywhere now, not just Google search results.
Thank goodness for the bot on Reddit that posts replies with the actual link, for any AMP links that are posted.