Why isn't trading strats used in rsg speedruns. It should negate the need for nether and enderman, correct? What's the flaw in this logic. The ssg speedruns use this, so why doesn't rsg speedruns use the same?

The strat is used for RSGP but it honestly doesn't look like a possible wr strat for RSG, requires an insane amount of luck and doesn't actually save time compared to regular strats which can technically get sub 20

Because there is no reliable way of obtaining that many emeralds easily and fast in pre-1.9.