Yes, you can build your own website
We are fortunate enough to live in a day and age where we have enormous amounts of information at our fingertips, and the access to learn just about anything we want to. When I speak to a potential client about designing a website for their business, my verbiage is rarely "I can do this and you can't, so you need me", it's more "Sure, you can do this, but should you? Is it a good use of your time?".
Time. That is really what you (the client) are buying when you hire a creative professional to build your website, design a logo, manage your social media, etc.
You are buying time first, expertise second.
Do I know more than the average person about designing website? Definitely. Can the average person learn to be just as much of an expert? Absolutely. Everyone (for the most part) has the access to the same information - it becomes more an issue of whether or not learning how to design your own website is a good use of your energy and time as a business owner.
So, when wrestling with the decision of "Should I hire someone? Or just do it myself?", consider the value of your time. In fact, put a dollar amount on it, figure out your hourly wage, and then consider this when making decisions to take on tasks that may take you away from what you're truly gifted at (which is typically where you are getting the most significant ROI). Is it worth it?