Over time websites can begin to look out of date. After some years they should get a redesign.
There’s a key point to be aware of here though, and it is this:
” if you add new pages to the website that is fine, but existing pages are probably in the google search results pages (SERPS). Care should be taken to ensure that these existing pages still exist with the same website address or customers can become confused when they click on your Google listing and arrive at your website but not on the page they expected…
You also need to ensure that the redesign maintains the branding of your business to some extent to ensure returning customers know they are on the same website.