1.93” mounts originally were a thing because that is exactly how high optics mounts needed to be in order to clear IR lasers mounted at 12 o’clock on quad rails.
As they got used side benefits such as the better vision and visibility of the more upright head position, ease of use with plate carriers, gas masks and NODS were noticed.
The move to higher 2.08 and 2.26” mounts is largely driven by NODS among actual users which in turn makes it fashionable.
For class / fast CQB shooting high mounts are advantageous, especially to those of us with less neck flexibility.
For longer range / SPR/DMR stuff 1.5” and now 1.7” are still preferable.