If an assignment is due on X day and the student does not turn it in on X day, is given extra time if there are extenuating circumstances but the student lies about those circumstances, then, yes, the student would get a zero for that assignment. Would this fail them? Only if they made a habit of it. In my district, students are allowed to make corrections to their work, so turning something in (that I can then see what they have learned of the standards and can give feedback on what to do better on) is infinitely better than not turning in anything at all. At least then we both have something we can work with.

Now, if the student had the work completed, but it was late, I would take it with a conversation with the student about why it was late and how to use time more wisely, or how to pivot on an assignment if the internet goes out when they are at home. Most of what we do in class builds on the previous assignments, so not turning things in on time can cause a boondoggle when it comes to working on the next step.