I'm not that surprised with the revelation that passenger numbers on the Metro have declined.

Punctuality and overall perception of reliability has declined somewhat in recent years (more reports of train/service failure through social media etc.,). Modernisation, although crucial, has resulted in the temporary closure of lines for long periods of time causing travel disruption during peak hours. And GNE probably haven't helped by running services like the 1X between North Shields and Newcastle in competition to the Metro Replacement Service between Wallsend and North Shields last year.

Of course, passenger usage only takes into account the number of people who have paid to use the Metro. It does not take into account fare dodgers, or people reusing old tickets left on top of ticket machines or whatnot. So maybe, the level of passengers using the Metro has remained the same, but the number of people paying for the service has decreased, further adding to the picture of decline.