Yes, but they don't transform when they use it, is the point. We're told that it's a technique and when other characters use it, it's depicted as such. In the manga, we even see Master Roshi using it and once again, it's a technique.
But when Goku uses it, he visibly transforms. He is literally the only character for whom Ultra Instinct works like this, and no explanation is ever given for why Ultra Instinct is a technique for everyone else but a Super Saiyan form for Goku.
So we're left with a weird case where Ultra Instinct is a technique and we're told it's a technique and we're even shown that it's a technique - but when main character Goku uses it, and because he's the main character he uses it more than anyone else, it's a transformation. Because fuck you, that's why.
It's supposed to be a technique but it's depicted as a transformation for Goku, and only for Goku, and for nobody else but Goku. Goku's transformation versions even get cool new names: Ultra Instinct Sign and Ultra Instinct Omen. What are "Sign" and "Omen"? Who knows! They aren't a thing for anyone that actually uses Ultra Instinct not named Son Goku.
Edited by TobiasDrake on Dec 23rd 2020 at 10:05:36 AM
My Tumblr. Currently side-by-side liveblogging Digimon Adventure, sub vs dub.
Sign and Omen are the same thing. It's just different names for the same concept.
As for why it's different from Goku, I believe Whis said even Beerus hasn't fully perfected it yet right? And when Roshi used it, both Beerus and Whis said it was a very rudimentary version at that.
It may also have something to do with Goku's God Ki from the ritual. Maybe that's having an effect.
Of course, this is all just conjecture on my part. The real reason is probably Shut up! That's why!
One Strip! One Strip!The rare moment when a Toei exclusive transformation overshadows the real thing.
Honestly, Omen makes it seem less like a transformation and more like an actual technique since Goku doesn't physically change at all. Its only when he gets the Silver hair that it becomes the standard transformation.
I honestly expected Goku to combine Omen with Blue for this very reason and actually make Blue feel like a godly form for once.
The silver hair is fine, but it feels like a blatant Merchandise-Driven move to sell a new Goku form.
A lazy millennial who's good at what he does.

One could argue there's ground for UI being both a Technique and a Transformation. Like, the two don't have to be mutually exclusive.