What exactly is the benefit that these platform companies derive from AMP? Last time i asked the claim was that google gets some "tracking" benefit by serving the amp.js file the pages have to include, which seems unlikely but whatever. But for Twitter, or Bing, or any other platform that is preferring to link to AMP pages over full-featured HTML, what is the benefit? It can't be tracking for them, they aren't hosting the amp.js file.

The only possible benefit I can see for Twitter to link to AMP is that their testing proves users prefer AMP pages, meaning a better user experience is result when "development is clearly steered by platform companies". When you say AMP is biased in the platform companies favour, what you really mean is it is biased in the user's favour.

As we've seen with the state of the non-amp mobile web, it's not simple to load quickly. Maybe it's simple to implement if that is your goal, but convincing all the involved stakeholders that it's a worthwhile goal is hard, and so the mobile web is slow as hell. The open web had their chance to make fast sites, and failed. So now an industry-led carrot-and-stick style approach is being used, and it's actually working. pages load fast now. And the HN Community, who is responsible for making a lot of those slow sites ("oh! let's load another three analytics platforms, it's only a couple megs") is angry.