If you are manually creating automations in yaml, use the first example you posted. The second example is what the UI generates and it’s not intended to be manually used.
I am not talking about manual yaml configuration. Both cases describe how I fulfilled the fields into the automation UI. So my question remains : why two UI ways to do the same ?
old way verse new way. People had issues understanding the old way (call_service) method, so a new automation method was born for people who didn’t understand.
There is no difference other than how you want to tailor your automations.