Why does Firefox upgrade action on MacOS require restart?

Under the site “Update for Mac Applications” that is published by HCL, there is content to upgrade Firefox on MacOS. The latest fixlet “Mozilla Firefox 123.0.1 Available - Mac OS X” calls for a restart after installing the pkg. I couldn’t find a specific requirement for that restart. Anyone know why?

While it’s generally not necessary in some situations, it’s always a best practice to restart the device after installing any software. Based on that, I think the majority of fixlets include the phrase “action requires restart”, which is a recommendation.

Fixlet uses the command “action requires restart” to indicate that action has completed & now pending for restart.