To maintain site compatibility, on Windows, Firefox detects whether touch input is supported and disables touch events on incompatible computers. According to a comment in the bug, compatible computers are only a few percent for now. On Android, touch events are enabled by default. On Mac and Linux, touch events are not implemented yet.
Compatibility issues with touch events have been found on many sites. If your site or application has supported touch events for mobile, please test with desktop browsers including Firefox to ensure it works as expected.