If that were the problem, then Electron wouldn't help in any way either. In fact, Electron is even less interested in platform conventions than something like S

If that were the problem, then Electron wouldn't help in any way either. In fact, Electron is even less interested in platform conventions than something like Swing. There isn't even default styling that tries to copy MacOS/Windows that you can apply. The bigger problem is actually desktop-mobile compatibility today. No one writes apps only for Windows and MacOS. You want an app that works on iOS, Android, Windows and MacOS, and typically on the web as well so people can occasionally access it from an unfamiliar computer. So, the only viable option unless you want to have 4 dedicated UI teams or so is to write it in the lowest common denominator of HTML/CSS/JS, and use Electron and WebView to distribute it. To a very good approximation, no one whatsoever cares about platform look and feel. In fact, most people actively prefer if they're using an app for it to have the same look and feel across all systems where they use it, including the web.