“If we take the prevailing translation, of objects traveling in straight lines until a force compels them otherwise, then it raises the question: why would Newton write a law about bodies free of external forces when there is no such thing in our Universe; when gravity and friction are ever-present?”
The author’s argument makes no sense. Newton was talking about what happened to an object in the absence of external forces. Which makes perfect sense if the rest of your laws of motion then define how forces affect an object.
Of course, relativity turns Newton’s fixed frame of reference all topsy turvy.
Einstein never meant to overturn Newton’s Laws. He just confirmed that they are appropriate and valid until about he 10th of the speed of light, and then they ‘kind of’ get a little goofy (in scientific terms).
It’s been several decades but I recall that just about every physics problem I had during college had to account for gravity and friction.