I'm not an airline transport pilot, but in my personal flying, I've declared emergencies twice and asked for priority handling due to minimum fuel concerns once. No paperwork on any of them.

I also spend significant time on aviation/pilot forums, and I've literally never heard of "lots of paperwork" for any emergency that resulted in a safe, no injuries landing. The topic comes up regularly in the "should I have declared an emergency or not?" discussions, the common argument against is "I don't want the paperwork" (a strange trade off against a life-safety question in any case), and the most I've heard as routine followup is a phone call from an inspector.

My experience is exclusively US, so perhaps it's different in other areas of the world.

Maybe there is a difference between parts of the world, but I would be surprised if airlines don't have some kind of routine to follow when an emergency is declared. And I would be even more surprised if airline pilots on Ryanair routinely used emergencies as an excuse without it having any consequences.

The only issue I've ever caused was triggering a TCAS warning for a landing airplane because I was slow on starting a turn. Even though there were VFR conditions and we were at a safe dinstance, the other pilots said they had to report it as a matter of company policy, and my instructor had to make a few phone calls afterwards.