I don't even own any gloves thicker than 3mm. If the water is not too cold, I will dive dry with 3mm wet gloves sometimes.
But, the reason I got dry gloves in the first place is that they offer better dexterity than even 3mm wet gloves.
The key for that is to have the right actual gloves on your dry glove rings, along with the right glove liners.
Many people use actual dry gloves that are WAY bigger than they need. Combine that with using gloves that are really thick and heavy duty and dexterity is substantially impaired.
I use Ansell G17 rubber gloves. They are the same glove that came with my original Kubi rings.
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They come in different sizes. I use a size that fits snugly (but not tight) over my medium weight wool glove lines, which also fit snugly on my hand.
They are only 30 mil thick, so they are not as tough as what some other people use. But, they last me a really long time. I generally try to make a point of not touching anything, whether I'm wearing gloves or not. If I were molesting lobsters or wrecks, maybe they would tear up quickly. But in that case, I would probably just get some thin cut-resistant gloves to wear over them.
Side note: People talk about using equalizing tubes to let gas move between their suit/sleeve and their dry glove, to prevent uncomfortable "squeeze" on their hands. I don't use anything like that. I've been to over 300' with my dry gloves and fully intact wrist seals with no equalizing tubes, and no problems at all. I attribute that to using right-sized dry gloves that don't have a bunch of extra air in them.
TL;DR: the right dry gloves, in the right size, have pretty minimal impact on your dexterity.