How can I set up Outlook once and use it on all devices?

I use MS Outlook on a PC, notebook and smartphone. I judge e.g. A new email address in Outlook, I have to do it 3 times. If the access data for the e-mail inbox change, I also have to maintain it three times.

Is there a way that I can set up Outlook centrally and synchronize Outlook on all devices? A link to a video where everything is explained / shown would be great.

No, there's not.

One way would be to do that through an exchange, but you don't want that.

Is there a way that I can set up Outlook centrally and synchronize Outlook on all devices?

No. Each installation has to be considered individually. If you change the entries, regardless of the device, you have to change the settings on all other devices.

Nothing would change with an Exchange account; This can only be simplified with SSO within a company network, but you still have to manually update all devices that are not part of the company network.