And well-developed third-party apps that integrate deeply into the rich macOS APIs. E.g., the other day someone posted Shortcat which provides keyboard shortcuts for every GUI application, by using macOS accessibility API (which apparently works everywhere, including in Electron apps):

https://shortcat.app

Another good (recent) example is Mimestream, a client for Google Mail, which is one of the best mail apps that I have ever used:

https://mimestream.com

Apps like that are not only a testament to the awesome indie developers in the ecosystem, but also the great APIs that make it possible to develop such application as a solo developer.