I think the entire psychological structure of academia leads to a tendency of procrastination. I don't procrastinate at work much at all, I procrastinated way too much in academia.
Properly designed academia would probably remove procrastination from K to PhD.
To add to the other response(s), there's a sense of artificialness to homework and the way it's drip fed.
The deadline is just so the setter has a schedule to assess it, and the next one will be coming at some point in the future.
With work it's usually all coming now. If you're not doing task a, you could be doing task b, c, d or e instead. Of course good planning and management will mean time is organised between all the tasks to get them done one at a time (or as close to) and it's not a daunting pressure, but I find there's always a sense that there's lots to do.
In the cases I've had where there doesn't seem like a lot to do, that's when I tend to procrastinate with what I'm meant to be doing, looking at this and that other interesting thing we could be doing.
I'm not OP but presumably: homeworks are done alone at home whereas professional works are done within a team at a workplace. Procrastination is the demotivating consequence of working alone, isolated.
Properly designed academia would probably remove procrastination from K to PhD.