Which is the best method of web development; WordPress or raw html?
As with most things, there is no “BEST”, there is “BEST FOR A SPECIFIC JOB”. WordPress is great for creating websites with high levels of functionality such as ecommerce and digital interactivity quickly. WordPress has thousands of themes and plugins which get you very far very fast and inexpensively. WordPress also gives an excellent portal to manage the site which is easy even for clients to use. The trade off is that it is bloated in comparison to most properly coded Raw Html sites because the Raw Html site will not have so much extra functionality to accommodate. With Raw Html sites, you can only include precisely what is needed and thus ensure optimal performance. Another thing to consider with Raw Html sites is that you will have to either build a portal to maintain the site, or be able to code it. For most sites, Raw Html will take substantially longer to create as well. I will not say one is more secure than the other as it depends on many things such as what plugins are being used or how security conscious the developer is.

Which method do you prefer and why?
I prefer using WordPress because it gives great value to my clients and also allows them to take control of their assets, they do not rely on me to maintain the site though I am always available. If the site needs to be super fast and secure, I personally would suggest Raw Html as I have expertise in security and can ensure secure coding standards.