LO Taunt Tomohawk is a large reason duggy stall isn't nearly as prevalent here compared to OU. Simply put, it's a really good breaker that can't be trapped by virtue of its typing. For comparison, take CM Tapu Lele for example. It's not an easy mon to switch into, and it would love to run Mind Plate or a Z Crystal to boost its offensive presence, but if it's not running Shed Shell, stall builds that have Dugtrio can still effectively limit its impact on the game. Shed Shell is obviously a wasted item slot in matchups against non-Dugtrio teams. Tomohawk has no such problem, meaning it's free to run Life Orb, and it can stay relevant for virtually the entire match with Roost.
Aurumoth (Illusion sets in general) is another reason stall struggles a bit more. Even if you have a mon like Unaware Clefable that can deal with most sets, you aren't always going to know exactly when to send it in, assuming moth is played well. "gee, that colossoil just used quiver dance! what do?" An error in prediction can be quite costly, and various Pokemon like Toxapex/Mollux/Tomohawk can end up going down in the process. Z Crystal moth sets, notably Psychium Z and Firium Z, have made it an even more dangerous mon for stall to deal with, as its surprise factor isn't lost after a single round of LO recoil (not to downplay LO moth's effectiveness; it's definitely still a strong mon). The kicker is that Dugtrio isn't really a great answer to Aurumoth. Aurumoth can technically be trapped since it's grounded, but it resists EQ and only takes like 50-60% from Stone Edge (and this is just 0/0 moth), which isn't always used on Dugtrio to begin with.
Basically, duggy stall in CAP struggles with two very good mons running good sets. This isn't to say it can't be effective, but like most stall builds, it tends to lead to incredibly matchup-based battles.