Well, maybe they shouldn't. Those popular apps are likely to be better just by virtue of being better funded. But if there were apps from the major players for every usecase, all programmers would be working for Adobe-sized corporations. Thankfully, that's not the world we live in.
Recently I've looked at apps for running a "flat owners' association" in the Czech Republic. The general feeling I got was that maybe one was at least approaching intuitive and good looking design. Using a cross-platform UI toolkit wouldn't hurt these apps one bit.
Besides, the only ones that supported macOS at all were web apps, the epitome of non-native. So if a non-programmer wants to manage such an association on a Mac, their only options are cross-platform apps or a spreadsheet, proving my point.
Recently I've looked at apps for running a "flat owners' association" in the Czech Republic. The general feeling I got was that maybe one was at least approaching intuitive and good looking design. Using a cross-platform UI toolkit wouldn't hurt these apps one bit.
Besides, the only ones that supported macOS at all were web apps, the epitome of non-native. So if a non-programmer wants to manage such an association on a Mac, their only options are cross-platform apps or a spreadsheet, proving my point.