I opened the Microsoft Store and had a look at the top 50 items in "most popular". It includes items with such mainstream appeal as the Windows Terminal, Ubuntu 20.04 and the VMWare client.
The most popular app is Roblox. It has 164 reviews. The second most popular app is Spotify. It has 57 reviews. On Android, it has 19 million reviews. Their Android TV app even has 200. The item with the most reviews is Minecraft, with 1000 reviews. On Android it has 3.5 million.
The Microsoft store also lets you install free apps with out logging in (if you keep clicking out from the login prompts) so it's probably also harder to get reviews.
The most popular app is Roblox. It has 164 reviews. The second most popular app is Spotify. It has 57 reviews. On Android, it has 19 million reviews. Their Android TV app even has 200. The item with the most reviews is Minecraft, with 1000 reviews. On Android it has 3.5 million.