Website navigation matters
Search is just one way that people will navigate your website. If people cannot quickly find the information they want, they will leave your website and look elsewhere. Mostly, people expect to see menus guiding them through the options, but menus need to be short and easy to understand. For sites with a lot of information, it can sometimes be useful to provide an alphabetic index or site map to the major topics.
Real people do not start at your home page
If your website is successful, people will find it in a search engine and go straight to the page of information which answers their question, the page which meets their need for information. Another possiblity is that they will have clicked on a link to an article on your site that has been shared on Facebook or Twitter. Most of your target audience will never read your homepage. Those that do are unlikely to sit through a caroussel of pictures or want to see a "Welcome to our website" message.
We all use the back button
The most universal navigation option on the internet is the back button. Everyone understands how the back button is supposed to work and it is always in the same place, on the browser button bar and on the keyboard. We all use it all the time without thinking, dozens of times each day. When a website page layout looks confusing, the back buton is always close at hand. On slow loading websites, or on sites with flaws in the navigation code, the back button may be the only option. Google reports that around 50% of mobile users are liable to hit the back button if a site takes longer than three seconds to load, and that percentage rises with every additional second of load time.