Hi DerfoBurfo,
The Mac App Store is different than the iOS App Store.
On iOS, the only permitted method for distributing apps is through the iOS App Store. Because of this, all of your favourite apps can be found in one place.
On macOS, developers can distribute apps either through the Mac App Store, or from their own websites or other sources. A lot of developers don't upload their apps to the Mac App Store due to certain restrictions the store imposes, as well as Apple taking a 15-30% cut of revenue. (This is unavoidable on iOS.)
If your Mac has the M1 chip (or future Apple silicon chip), there should be a category in your search results called "iPhone and iPad apps". Due to the architecture used by Apple silicon, those particular chips can also run iPhone and iPad apps. (Intel-based Macs do not have this capability.)
In your case, Netflix doesn't even have a macOS app (as mentioned by Barney-15E and Old Toad). It can be accessed online in a web browser: https://netflix.com