Since now most people use a SSD or M.2 drive for the OS and Windows 10 users have there operating system on a USB Flash drive formatting is way quicker. But remember eventually you will end up at the same point down the road. Better to just Defrag (Only if you have a HDD), Trim and clean up your windows before you decide to format and reinstall. If you are having problems fresh installs don't always work and fix the problem and if they do it can be temporary.
Also if a fresh install fixed a issue then you could have avoided the issue by searching possible fixes or asking around.