What do I use to replace Safari?

Try another browser as a test.

Firefox        10.9 or higher.     

Opera Browser        10.9 or higher.    

SeaMonkey      10.9 or higher8.     

Waterfox          10.8 or higher.    

If running Mojave or Catalina, you can also try Safari Technology Preview. Go to Safari/Preferences/Advanced and check Show Develop menu in menu bar. Go to the Develop menu and select Get Safari Technology Preview. Open from the Applications folder.

For the IOS version, go to the App Store and download the desired browser.

Why? What is the problem with SafarI?

Are you trying to update Safari/macOS or Safari/ iOS ?