Disable is just what it says nothing more nothing less. Put this way your on the internet your ISP collects your data and any sites you go to collects data and cookie to track. So if you block everything your cutting the internet off and blocking cookies will block you from accessing site. The internet is a give and take unless you go to black sites then that is user responsibility at that point. Even you O/S collects data because if you didn't agree to the TOS you couldn't use it just like getting your ISP you agree to their TOS. So these are examples user forget to look when they make general claims about stop collecting data or cookie tracking.

Hi Bob, when an extension is disabled, none of its scripts run, so it can't do anything.

And now, some more general thoughts.

The fact that an add-on can read what is happening on web pages you visit doesn't necessarily mean that information ever leaves your browser. Many of my add-ons, for example, need to be injected into pages automatically when you load them, but they don't export any information out of your system. I would rather not know what y'all are doing on the web. Really!

Unfortunately, it's difficult to know exactly what an add-on is doing when it's enabled. A variety of people write add-ons, and if you don't trust an add-on's author with the permissions you grant to the add-on, you probably should remove it.

Things are starting to change for the better. Traditionally, you couldn't easily prevent many add-ons from running on particular sites, it was all or nothing. Many newer add-ons have an updated permissions system where you don't grant permission to read site data automatically at install time, and instead you do it on a site-by-site basis. But this approach doesn't work for all kinds of add-ons, so we'll still have many all-or-nothing choices for the foreseeable future.

This site has a general article that might be useful: Tips for assessing the safety of an extension.