the shift to offense really didn't change musharna's viability much. sure cm is worse because there is more things it needs to "wall" but on the other hand, musharna has an easier time walling things because there is more weaker but fast threats than stronger but slower threats. the strongest + slower threats are worse for mushy because she's gonna be outsped by them anyways. you don't see things like guts ursaring or zangoose much anymore who could rip through a musharna easily. offensive teams have issues switching into musharna too because they risk getting crippled by thunder wave, so just because scolipede can break through mushy doesn't mean offense has no issues with mushy. you need a good portion of your team to be able to beat mushy for it not to be an issue. it takes such a long time to beat mushy that by the time you do, she's already crippled some of your team, and did some moderate damage. substitute and taunt aren't really good arguments against musharna because she easily does over 30% to frail offensive mons with psychic. there's mandibuzz sure, but that's not much of a hyper offensive pokemon. mandibuzz does also not want to risk getting status'd at all, otherwise she loses most of her potential. she wants to be in at the same time as the mon with status so she can shut it down. mushy is also a very good momentum grabber which is sooooooo useful for offensive teams. having momentum over the opponent is the key to success on these offensive teams as they allow your mons to overwhelm the opposition with ease. she's the same viable as she's always been (which was pretty much the most consistent and dependable mon in the tier), just the way she plays is slightly different in this meta.