Probably because they made an exclusive financial deal with Moderna and nothing to do with the efficacy of Pfizer. As the man said, "follow the money."
I don’t think so - they never made an official announcement as to why they were switching but around the same day as that haaretz article I linked there was another article where Israel reported that they were seeing HUGE spikes in the Delta variant and that by their studies they were only seeing Pfizer as 30% effective:
https://www.cnbc.com/2021/07/23/delta-variant-pfizer-covid-vaccine-39percent-effective-in-israel-prevents-severe-illness.html
Note Fauci is doubling down on Pfizer here so that might be your money grab (there’s also conflicting studies from different nations about Pfizer’s Delta efficacy - but when Fauci’s involved I’d put money first...)