Simpler doesn't necessarily have to mean AMP, though. If Google really wanted to improve performance, they could just create some simple requirements - "if you want to appear at the top of the search results, your page can't take more than X seconds to load, use more than XXX kb of data", etc, and show warnings in the search console to websites that don't comply. The only reason to create AMP is to increase Google's control over websites so they can make more money selling ads.