Is Safari becoming obselete?

What data are you concerned about? This is just cached history and occasionally site settings. Presumably your useful web addresses are saved elsewhere as bookmarks?

If you don’t want to go that route, all I was suggesting is that the web address for the bank might be outdated. Financial institutions are known for doing that when the layout of their websites changes. Find out the current address, start using it, and it will be “remembered” in addition to the old one.

If you’re clicking on a saved bookmark, or a web address, update them. They are likely outdated. You may also want to clear Safari history and web data, in case the old address is being retrieved from there.

Try this browse...

https://brave.com/

For one it's a troubleshooting action, but I see you do not need any help in figuring out where the problem is.