This argument is errantly conflating two separate ideas: retakes and deadlines.
The act of allowing a retake does not preclude the use of deadlines. Setting deadlines for initial work is important because that way, I can check student work before the major assessment. There are also deadlines for completing retakes…the end of the semester being the hard stop.
I'm also building in structure for retakes. The fact that I allow a retake does not mean it happens when and where a student wants. They work within my defined schedule, which includes deadlines.
Arguing against retakes because deadlines disappear assumes that they are contingent upon one another when in reality, they work together to help students develop agency and time management skills.
This makes sense at a high level, but in reality, none of us - in school or out of school - lives in a deadline free world. I have deadlines to meet at work and if my product is not quality at the deadline, I have to do it again.
The difference is that we cannot fire students from school.