Two years ago I released a Mac app (https://heyfocus.com/) that couldn't be in the MAS due to sandbox restrictions (tried 3 times—frustrating experience).

I sat on it for an entire year because I was convinced nobody buys stuff outside of the AppStore anymore.

A year ago, the project still had really good traction, so I decided to try to sell it directly as a test (using Paddle.com).

Boy, was I wrong! TONS of people buy outside the MAS, and Focus is doing better than ever. If you're questioning it like I was, give it a shot.