I don’t mean to sound overly negative but for small shops or individual developers there is simply no way for them to create a web, Mac and Windows version of their app at the same time. Personally, I’m glad that the likes of Electron give them the option. I’d much prefer a fully native version but I’d take Electron over nothing. You’re free to disagree of course, but no one is forcing you to install these things on your computer.
The problem this solves is that web apps don't have (1) cmd-tab icons or (2) decent notifications. And it does that without using "cross-platform tools" or "electron". That's why it's cool.
The closer analogy here is the iOS ecosystem, where folks ship apps that are really just Safari WebViews inside an app icon, and who would probably be perfectly happy to ship a PWA if users weren't thoroughly trained to use the AppStore.
what’s the best cross-platform strategy?
In reality, rarely do you need to work on the UX first. It is usually more wise to sketch the idea using cross platform tools, validate the idea, then rewrite parts of it / develop new features with native technologies.