Native software is incredibly difficult to build well.

There are at least 4 platforms they would need to support: Win, Mac, iPhone, and Android.

That's 4 different software engineers at least, just for the frontend.

Then, there's various backend engineers, who could be shared, yes, but not always. Android's weird runtime requirements are bespoke enough that just because the database is written in C++, doesn't mean it's the same C++ database as what the Windows backend would use.

Finally, there's the designers, who end up consolidating all the unique things about each native platform into a common design language so they can have a shared vision on all of the platforms. So engineers end up building UI that works identically on all 4 platforms, and you're basically building a bespoke "browser" at that point.