Processing delays, instability of the program, and the fact that there's no automated extension for C33 EADs.

If we got the 180 day automated extension when a receipt notice is printed people would be way more likely to file I-765 a bit closer to the expiration date.

If we had some kind of a reassurance that the government won't pull the rug from under us we'd similarly file a bit closer to the 180 day mark. Hell, I still remember the injunction in early 2017 where I filed 14 months before expiration because I had no guarantee that this injunction would hold for long. I think at the time I was one of the earliest renewals on this site, people were outright surprised that it got accepted.