"Ryanair requires that all non-EU citizens report to the check-in counter to verify their immigration status" (quote). Let's leave discussion about "why" aside for a moment. This question is about "how".
In my recent experience, they do it twice. The first time is at the "Check-in/bag drop/visa check" desks (sometimes these are separate). The second time is at the gate during boarding. As far as I recall, they have done it twice on all of my recent flights. However, why do they do it a second time?
It is reasonable to match your identity, passport, and boarding pass at the gate, and there are no questions about this. But for whatever reason, they always recheck the visa as well. Why? The visa check stamp is already there, and it is mandatory to perform the visa check at the check-in desk. So what is the point of spending additional time verifying the visa again?
Alternatively, if this happens to be the new way that the company operates, does it mean that the visa check at check-in desks is no longer required?
Note that if you are flying out of Schengen, you also have to go through immigration passport control, and those officers can also verify that you hold a visa to your destination. This is fine and not the subject of this question. The question is specifically about the additional visa check that Ryanair performs at the boarding gate.