but instead Bayes theorem is used for everything :)
Bayes Theorem is useful, and prof. Sebastian Thurn has described it in AI-class, as well as "Robots" class, and now in "Statistics".
This time, he provided a visual description that is helpful.
Here is another useful site with similar description.
Visualizing Bayes’ theorem | oscarbonilla.com
For some reason, many Bayes descriptions are using "cancer" as an example.