Wheel Incompatibility between Python Minor Versions

I’m releasing a package on PyPi which will support Python 3.6+, and would like to build as few wheels as possible. I’ve read up on Python’s packaging system for wheels and looked at the NumPy project for an example. Reading PEP 513 and PEP 571 was also insightful. Here’s the question: why are wheels forwards-incompatible with Python minor version changes? Upgrading from 3.5 to 3.6, for example, brings f-strings. But it seems like a wheel built with Python 3.5 (not using f-strings) should be able to run just fine on a Python 3.6 environment. What’s the issue here? Answer Code