If I remember correctly, the entirety of the original GSM is ~9000 pages, things just got crazier (by orders of magnitude) from there.
That's comparing apples to oranges, though. Those standards also specify the interaction between network components, not just between your phone and the network.
Mobile phone standards are more like the entire RFC collection than like the 802.11 specifications.
...and the GSM/UMTS/LTE/NR standards are at least an order of magnitude even bigger.