Evaluating my 2023 site analytics -- why did my traffic drop?

Once a year, usually at the beginning of January, I look at my site analytics with the latest numbers from Google Analytics and also reflect on trends, changing directions, and other metrics for the year. This weekend I updated my site's analytics for 2023. The metrics were kind of harsh for my site this year. Page views were down 35%, users down 37%. Page views per session were down 12%. My top 30 pages were almost all to pages in my API documentation course — almost none of which were new in 2023. Accounting for the shift could be the many changes to Google's search algorithms, the changes in Google Analytics itself, the layoffs and industry slowdowns in tech comm, the expanding influence of AI, stale content, and other reasons.