Just because core is supported...

Just because Drupal core is supported, it doesn't mean that all of the other modules your project uses are still also supported or actively worked on.

Since the Drupal 8 release in 2015, I've seen numerous examples of modules that haven't been updated for some time as maintainers focus on writing and maintaining the versions for Drupal 8 and now 9 and 10.

Whilst it isn't marked as unsupported, it isn't being updated either.

I recently explained to a client that their site uses a module last released in 2014. It's buggy, but there's no newer version to use and issues in the queue are no longer being fixed or triaged.

Override Node Options - a popular module I maintain - is in a similar situation. The most recent Drupal 9/10 version was in February 2023, whereas the last Drupal 7 release was in March 2018.

I don't have any official figures to support this, but feel the contribution rate for Drupal 7 projects (as in modules, themes and distributions) has been slowing for some time.

Meanwhile, Drupal 7 core is still supported, at least for now.