Having had (and sort of continue to have) issues with Nitrates, I have done a fair amount of research and thinking about detritus, food, poop, etc. I think it is useful to compare salt water experience and practices with freshwater ones. While there are key differences, there are some basic things that have to be same.
From what I can tell the big salt water advantage is that they can protein skim relatively easily. It is possible, though difficult, to protein skim in freshwater. The koi people (and the koi world is a good one to occasionally look at - they keep very, very expensive and dirty fish so spend lots of time and money thinking about how to do it effectively) have figured out freshwater protein skimmers, they are big, loud and expensive so not terrible practical for in house aquariums.
Protein skimming combined with aggressive mechanical filtration (via filter socks) or biological filtration (via algae scrubbers) is likely pretty effective. I think the key on the mech side is that salt water folks change their socks aggressively like several times a week.
Lightly stocked tanks, skimming, mech filtration, and some amount of biological de-nitrification does the trick for them.
What can we learn?
Mechanical filtration accompanied by throwing out the detritus could matter in the freshwater world - but probably doesn't too much for us. Why? Well if you think about it detritus gets trapped in the filter. It does not immediately breakdown in NH3, it takes some time. For salt water people they are basically taking out a lot of detritus before it breaks down, by changing socks several times a week. Most freshwater people can't or won't do that (although I wish I could experiment with aggressive mech filtration and removal, would have to redo my sumps though). So virtually all detritus in a fresh water system eventually breaks down. This is why you don't need to clean mattenfilters, etc. You just plan for that to happen and fix it by changing water.
The point to me is that different processes are not happening, just that we are dealing with it differently. We do this as water changes are (relatively) cheap and simple in fresh water and most of our fish are not as lethally effected by NO3 as coral is so it makes sense to do so. It is not something fundamentally different that let's a mattenfilter go a year without cleaning, just a different approach.