Impossible to judge in a vacuum. How big is your kitchen? How big is the cabinet base of the island? etc.

What does your designer say?

That's a continent, not an island. You won't be able to reach the center to clean it. And certainly not to use as a work surface. Anything that isn't functional isn't right.

IMO that is a very large island but in the right space could be fabulous . My first question is can you get it into the space sometimes pure logistics won’t allow a piece that size to fit around corners for install. How much seating some pics of the space or a floor plan would help us as far as getting a feel for the space. My island is 54” by 108” there is no reason why you can’t reach the center unless you are a kid and I find mine totally functional , I use it as a work surface for 2 of us all the time and when we have parties the food and booze are set up on it so very functional

PLEASE make sure if you have an overhang it is properly supported with metal supports that are attached to the cabinets. Especially on a slab that size.