Recently bought an Adafruit Industries board which controls stepper motors over i2c. It has a Phython library, but my code is in C++. Decided to convert the Python code to C++ to get started quickly. Behold the magic line that made everything work:

std::this_thread::sleep_for(std::chrono::milliseconds(10));

I can't believe Python's ridiculous performance is being harnessed to let the field generated by electromagnets in a stepper motor to grow to sufficient proportions to affect movement. Without the said sleep(), the stepper motor just vibrates with my C++ code. Not sure if the library was created with Python's performance in mind, or they simply didn't think about back EMF in electromagnets...