Not to slander the fine folks of Mojave or Tehachapi, but I'd venture that most folks are just "passing through" with at least a couple hours of driving both before and after. So whether one has to stop to charge around here or not, most likely to be coming through during the day. I'd even go further to say that those on the SF<->Vegas route are concentrated within a few hours around noon - it's a 9-10 hr drive WITHOUT supercharger congestion. Short enough that no one will stop overnight, long enough that folks will plan lunch between Buttonwillow and Barstow, so as to not have to start or end the trip at 4am or some ungodly hour (ignoring the party-all-weekend Vegas crowd, that would be a whole different beast).
That pretty much ensures then that SF <-> Vegas will all stack up at Buttonwillow and Barstow/Yermo and ensuring 72kw max at those V2 chargers, adding another hour or more to the ABRP estimate since you can't charge at 100kw+ speeds. And sure some can skip Mojave, but it means taking an even longer, slower sip of electrons up to say 90%, adding even more time. Conversely, folks on both longer and shorter routes to/from SF don't have as much need to leave at the same time of day, so have more flexibility to find Mojave uncrowded, or skip it altogether.
Indeed, at least the Google Maps congestion data for the Mojave supercharger, shows during the weekdays a highly concentrated mid-day peak, with very little activity in the morning or late afternoon. Congestion data for Buttonwillow and Barstow do have mid-day peaks, but are also more variable, since there are people traversing many different itineraries at different times.