>If this is true, then why are even bigger players with more resources like Facebook and Microsoft building on top of Electron instead of building natively?

Because software is a pop culture, and the latest fad always prevails at most shops. Also companies care more about cutting corners and shipping sooner than about the long haul.

That said, it's not like Facebook particularly enjoyed web based apps: "Mark Zuckerberg: Our Biggest Mistake Was Betting Too Much On HTML5"

https://techcrunch.com/2012/09/11/mark-zuckerberg-our-bigges...