Why convert? I find it pretty easy keeping an amp and non-amp version on the same codebase. Just a few switches what's activated where. And many of the restrictions (images with set sizes, no style tags, no use of !important) make a lot of sense for any page. And going once through Bootstrap CSS and deleting everything you don't need also helps improving user experience.

If anything, supporting AMP has accelerated my non-AMP pages a lot.