One major advantage Firefox, Chrome and other browsers have had over Edge is a rich extension ecosystem. In comparison, Microsoft has struggled — massively — to compete in this area. To be fair, it had to win people back to Edge first, which it's managed to somewhat accomplish. And while extensions for the browser are still thin on the ground, the steadily growing collection now has over 70 options.
As senior program manager for Microsoft Edge Colleen Williams explains, it was only a year ago developers were given the ability to plug into the browser and create extensions.
Rather than open the floodgates completely, Microsoft took a more curated approach:
Throughout 2016, we worked closely with a small group of partners to launch a core set of highly-requested extensions through the Windows Store as part of the Windows 10 Anniversary Update. The first extensions in the Windows Store were AdBlock, Adblock Plus, Amazon Assistant, Evernote Web Clipper, LastPass, Mouse Gestures, Office Online, OneNote Web Clipper, Page Analyzer, Pinterest Save Button, Reddit Enhancement Suite, Save to Pocket and Translator for Microsoft Edge.
This subset has now expanded to include "over 70 extensions worldwide" with "more every week".
Even so, Microsoft is sticking with a "purposefully metered approach" to extension development and inclusion:
We are extremely sensitive to the potential impact of extensions on your browsing experience and want to make sure that the extensions we do allow are high-quality and trustworthy. We want Microsoft Edge to be your favorite browser, with the fundamentals you expect – speed, power efficiency, reliability, security. Poorly written or even malicious add-ons for browsers remain a potential source of privacy, security, reliability and performance issues, even today.
It's certainly a different way of doing things compared to Mozilla and Google, but if it's working for Microsoft, then I don't see why it'd change things up.
Objectively speaking, if you're covering the basics, it might be good enough for non-power users who almost certainly make up a large chunk of Edge's audience.