An article called 'I am Officially Sick of COVID-19' got me thinking about this non-literal usage of 'officially'. I'd be interested to hear some explanations of how to correctly use this.
My feeling is that 'officially' is often used as a kind of emphatic way to demonstrate some kind of strong emotion. It also seems to present a logical conclusion, after you have listed some reasons for your emotion. In the article, the writer lists the many aspects of COVID which have negatively impacted his life. The punchline is then 'I am officially sick of it', implying a logical connection between the list of reasons. A literal usage of 'officially' hints at a systematic process which provides something with validity. The 'validity' aspect seems to carry over to the non-literal usage.