Yessss, more or less. I learned of the idea from this guy's content[1] who bikepacks ultralight and wants to save camping stove fuel, and he made his own. And from my dad who habitually wraps a thick teatowel around stew pots, on principle (he doesn't measure for a difference in power use. Electric cooktops only, not flame ones). Since it has to be snug on the pot, making one is probably the common way forward.
A few products do exist in that ultralight camping world, the Toaks D95 Pot Pocket[2], the Trangia Pot Cozy[3], Glacier Minimalist "pot with insulating sleeves". In standard size maybe the "So-Vida Sous Vide Insulation Band and Mat for Pots - Protects Your Work Surfaces and Saves You Electricity From Increased Insulation"[5] which is out of stock.
The Wonderbag[6] marketed as for communities in Africa and not available in the USA. From the Wikipedia page on Thermal Cooking[7], in a normal size kitchen people probably go with a vacuum flask cooker, popular in Asia.
Is this a product that exists?
The closest I could find was ceramic fiber insulation [0], which could presumably be cut to shape and fastened (high temp fastener?) into pot shape.
[0] https://www.amazon.com/s?k=ceramic+fiber+insulation