Dualies really aren't, and they certainly aren't meta as a whole in the competitive sense.
Dualies have the dodge roll mechanic, but the mechanic itself is not flawless, all dodge rolls come with a degree of end lag after they're used the maximum number of times. Meaning you're a sitting duck for those frames. This might be relatively short, but experienced players can take advantage of any type of frame disadvantage and the dodge roll end lag is one of them. This is especially true to the Tetra Dualies, which force you to stay in place for about a whole second if you use up all 4 dodge rolls in succession. Then also the simple fact that dodge rolls are pretty ink guzzling.
Then comes that Dualies do come with naturally less accuracy compared to other weapons. This isn't really noticeable with the Splat and Glooga since their accuracy separated is still about the same as a Splattershot (accuracy is increased to Splash-o-matic tier after roll). But the Dapple, Squelcher, and Tetra Dualies on the other hand you do feel their inferior accuracy outside of dodge rolls.
Then comes the fact that typically, Dualies tend to be slightly inferior weapons to their closest Shooter class equivalents, the dodge rolls typically are what make up for their below average performance.
Then you still have to account that subs and specials also play a huge role in the viability of the weapons.
Dualies are good weapons for the most part, but they aren't breaking any barriers. Dodge rolls are a fine mechanic, and as a Splat Dualies player myself I take great advantage of them, but they aren't meta shifting.
In typical play, Dualies are a pretty common weapon type seen, they're simply pretty decent weapons. They're also the new face of Splatoon 2. But they're not collectively meta, nor are they particularly OP.
