According to the Microsoft Store, Edge currently has 98 extensions, as of today. In comparison to the tens of thousands of extensions that support Firefox and Chrome, this number seems rather diminutive.
This may be for a variety of reasons, from Edge's smaller age in comparison to its competitors, to Microsoft's apparent effort towards ensuring that only top quality extensions make their way to the Store.
It may be for this reason that Microsoft is now exploring a way to give its existing extensions a bit more visibility - a number of users have reported recently that the Microsoft Store is showing a dedicated tab for its Edge extensions. Previously, one would have to open the store and either scroll down the home page a little to see a category of apps titled "Edge Extensions", or explicitly search for an extension they might be looking for.
This new tab features a number of curated extensions separated by their respective functions, with categories such as 'productivity' and 'shopping'. At the very top, there's a category for the most recently released extensions.
The testing process for this tab seems to be Insider Program-agnostic; this tab has been seen both by users enrolled in the program, and those who aren't. Granted, this may just be an A/B test to see how well this sits with users, so there's also a chance that after a period of testing, this tab will either be rolled out to all Windows 10 users or scrapped altogether; there's not much we can do until that point beyond speculate.