Comcast discontinued their old home page and replaced it with Discovery Hub. See the following: https://www.xfinity.com/support/articles/new-xfinity-online-experience
There have been many negative reactions posted in their user forum such as the following: https://forums.xfinity.com/conversations/signin-and-account-management/what-happened-to-the-old-home-page-the-new-discovery-hub-edited/6483764fd047d97dfff006be
There isn't anything you can do other than complain to Comcast.
You can however, change your home page in Safari to virtually any page on the internet or to a blank page. To do that open Safari, click Preferences on the Safari menu, click General at the top of the Preferences window, and change the Homepage. One easy way to do that is to first navigate to the page you want and then use the "Set Cto Current Page" button in the above Preferences window.
On an unrelated matter, if you are still using Safari on a Mac running macOS13, for security reasons you may want to consider either upgrading your macOS if possible or using a different browser.
If you want to know if an upgrade to your macOS is possible, please reply with the model year of the Mac (available at Apple menu > About This Mac).
If you can't or don't want to upgrade your macOS, for security reasons you should consider using a 3rd party internet browser that supports their current version with your older macOS. Two examples are Chrome https://www.google.com/chrome/ or Firefox.