As I've been creating Joomla websites for many clients for a couple of years. I need some kind of confidence to assure my clients that Joomla is still one of the top 10 CMSs and is still progressive and competitive.

For the time being, Wordpress community on StackExchange has 69,636 questions and Drupal has 64,256 questions. Meanwhile Joomla only has 4,139 questions.

Such a huge gap means Joomla is no longer popular or dying or lack of community support?

Is there any statistics, usages or trend that suggests I should still stick to Joomla?