For the performance per wat that they deliver, it's actually an improvement in a certain way.Every year the same "Oh the new chip will give massive battery life increases because of efficiency." It never does. Even when the M series were introduced in Laptops Apple had to put the largest battery allowed in a laptop you can travel with in order to get the type of battery life it gets.
These chips just don't ever give what people think they are going to give, at least not year over year. Every year we will just see small, incremental improvements.
You can do things faster and more efficiently while keeping great battery life. If you don't spend the same amount of time doing certain tasks, then your battery will last longer... again... in a certain way this is true.