I started out on friction shifting right around the time that shimano came out with indexing. I quickly moved over to indexing and never gave it another thought as it works better. Fast forward 40 or so years and I find myself running friction but that is because I like building and riding older bikes. Another reason you might want friction is cost if shopping for used bikes. Most of the deals on used bikes tend to be for friction shifting which makes sense since these typically are pretty old bikes.