One other aspect of this not addressed here is how much inventory of PZ is released and used in reality vs. PN space. Yes, I get that it's frustrating to see PN7 PZ0, but I also wonder how much of the challenge in using GPU's is related to the fact that with so many 1K's and GPU's as the main means of upgrading, the space just goes very quickly.

As an example, I monitored PZ space very closely last year on LAX - SYD and while PN space sat unused for weeks, the day PZ space opened (at PZ4), I immediately confirmed into 2 of those spaces and within ~6 hours the rest was gone. The GS pool is much smaller and GS has many more means to get into business class with GS benefits so there's a visibility issue in all of this - if PN space sits available much longer, it will always be very visible that there's availability, and with so many 1K's, a lot of the PZ space that comes available gets taken very quickly and thus you will see PZ0 the majority of the time.

Just thinking the comparison of total PZ vs. PN space released and used on aggregate each year would be slightly different from anecdotal searches, and given GS numbers vs. 1K, even if PZ space doubled, a majority of folks would still be unhappy.