

Even the Wikipedia article points out sweet muffins are only really different in that they’re usually not frosted and I’ve seen plenty of bakeries do that too.
They may have once been different, but modern American muffins and the mixes bought in stores frequently have more sugar than cake batter while using the same ingredients. They’re just breakfast cake.
Can’t be done is usually shorthand for the cost massively outweighs the benefits. No different from remodeling a building. Like coding, literally anything is theoretically possible but sometimes you’d have to redo so much existing work it’s never going to be worth it.