"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. First time on a "Check in/bag drop/visa check" desks (sometimes those are separate). Second time is on the gate as the boarding happens. AFAIR on all of my recent flights they did it twice. Why do they do it second time?
It is very reasonable to match your identity, your passport and your boarding pass at the gate, no questions here. But for whatever reason they always recheck the visa as well. Why? The visa check stamp is already there, you get it on the desk, and doing visa check at the check-in desk is mandatory, so what's the point of spending additional time verifying the visa again?
Or, if this happens to be the new way the company operates, does it mean visa check at check in desks is no longer required?
Note that if your are flying out of Schengen, you also have to go through immigrations passport control, and those officers can also verify that you hold visa to your destination. That is fine, and not a subject of this question. The question is specifically about additional visa check Ryanair performs at the boarding gate.