I am a one-man dev. If I can do it, I believe these million dollar company can also

They could if they wanted to. Heck, they have so many developers and money, they could even maintain a separate Cocoa app. But in all these cases, they'd rather externalize cost to the user.

Sadly, for many of these Electron apps, it would probably be better to install the iOS app, but most vendors disable that option.