WordPress is one of the best content management system which can handle any type of site easily. It is handing many big sites which are getting traffic in 6 and 7 figures monthly. WordPress is also a free content management system which makes it best.
Today, Millions of sites are dependent on WordPress. As per your theme or code of the website, you will have load time. If the size of the code will be more then it will take more time to load and if code will be simple then it will load very fast.