To explain further why dugtrio isnt the problem I'll show this replay of a battle I just had on the ladder.
http://replay.pokemonshowdown.com/gen7ou-539254229
I am be blood my Hiye and my opponent is using stall with shedinja + dugtrio. I realized pretty soon that: 1-Shedinja walls half of my team (fini, koko, metagross and phero cant touch it); 2- Sab+Skarm are preventing my lando from setting up stealth rock: without stealth rock shedinja is pretty much free to come in every time on literally everything. My opponent did not need to send in dugtrio once and still won the game easily.
tl;dr: as long as sab stays in the tier things like shedinja or dugtrio will always be "broken".
I'll now go into more the details on which steps I believe we should take in order to improve the metagame:
- There's too much broken stuff right now. Offense vs offense matchups often come down to which phero is gonna get the speed boost/quiverdance first. Balance is unviable because Metagross/Greninja/Phero/QD Volcarona/CB Hoopa are simply too much to handle. All of a sudden Stall becomes the most reliable playstyle because its the only way to not lose games at team preview.
- Now, lets say phero or greninja get banned: chances are we will see more of these SD Gliscor/NP Togekiss/Taunt Mew. These pokemon completely shut down Stall and they dont care about dugtrio.
- Another option that I have been promoting for a while is a suspect test of sablenite. I honestly dont get why sableye mega gets overlooked so much but in my eyes it has always been the primary reason to why stall has been so consistent throughout oras and now sumo.