If you notice that AMP is causing conversion decreases, I would have to suggest avoid using it.
You do not need to rely on AMP to improve mobile page rank.
Try doing things like keyword-optimized internal linking (perhaps via a Related articles section at the end of your posts), and mobile footer optimization. Be sure to use structured data (Schema) wherever possible as well.
Remember to build quality backlinks to each page you hope to rank.
In my experience, many sites do benefit from using AMP for faster page load speeds, but usually at some cost to conversion.
If any questions come up, shoot me a message.