My experience with very highly paid frontend developers is they like to spend hours and hours (and thousands and thousands of dollars) building out little libraries and components and frameworks that will enable other teams to be faster. Except this never eventuates because things rarely turn out to be reusable along the right axis so a new component or library or framework is developed to solve the problem.
On top of this UI developer propellor-heads love to spend time (and money) pontificating on abstract theories about functional programming and homomorphisms and endofunctors so they can render some text inside a <b> tag. It's how we wound up with utterly ridiculous pieces of code like the "hooks" API in React.