In my opinion, the lack of a congregation was the primary reason for the Resistance failure to launch.
It was the original cause of friction between Pfeiffer and Williamson.
By the time +Faure was consecrated, mid 2015, the Resistance was already 3.5 years-old, and most priests had already made their decisions.
Too little, too late.
Everyone understood that a Resistance movement formed according to independent pockets of resistance, without any means of reproduction (except along the lines of questionable formation we see emerging now) was a death sentence.
Yes, and I've always disagreed with Bishop Williamson for not putting SOMEthing together by way or organization ... that could have reined in the individuals who later became loose canons. Now, it needn't be a strict "Society" of any kind. One of the issues with SSPX has always been the "one size fits all" notion of priestly vocation. Before Vatican II, there are dozens upon dozens of options for how to live out even a priestly vocation. Some young men are more contemplative, others more academic, others more pastoral, others more "ora et labora"-minded, etc. That's why there are so many orders in the Church. But the SSPX has always had this tendency to shoehorn people into a certain type of vocation. In addition, they also do weird things like force priests to go off to Zimbabwe to live in a straw hut for years, without the priest volunteering for it. Not everyone is suited for that kind of thing. I have to believe that the breakdown of Father Stafki was related to his time of forced service in Africa. Not everyone is suited for the hustle and bustle of doing the mission circuit. And so on ... But a loose-knit organization of "Resistance" priests could have been very helpful, to help connect priests with congregations, to provide more centralized seminary and other resources, possibly build out some schools and retreat houses and the like, and most importantly to give the priests some kind of "anchor" so that they don't end up being wanderers (which is, for some, a recipe for disaster).