I agree that STEP files are not parametric. But for cases where thats all you've got, Altair Inspire is pretty good at letting you use them in a CAD system:

https://altair.com/inspire

It identifies features as such even from step.

Yes, but is it even saving you any time, then? For complicated parts, maybe, but the example above is not complicated and the AI is already doing a pretty terrible job. Someone familiar with CAD is able to quickly do this in 15min or so, and then you have all the history and constraints to adapt the design simply by just changing parameters. I'm pretty sure I'd spent much more time fiddling with a rough approximation in the form of a step file.

Even simpler tools like Solid Edge in synchronous mode will do a decent job of editing STEP files, as long as they're not just full of polygons.