I could imagine that the cash cow part of a product gets all the attention in the beginning. Does that stay the same through the life cycle? Or do you see that

I could imagine that the cash cow part of a product gets all the attention in the beginning. Does that stay the same through the life cycle? Or do you see that it takes a back seat while feature development on top of that takes the center stage at alter stages of the product? [edited to add this] I also see that it's sometimes easier to build something new, than to go on maintaining something.