I was under the impression electron is chosen less because of broad cross-platform concerns and more because chat apps, specifically, require a level of care in text rendering that nobody really wants to design from first principles when they can just piggy back on web technologies.
1. generally done well by many different UI frameworks
2. generally done better by most popular native UI frameworks than what Electron provides
BUT - those UI frameworks are typically not (very) cross-platform. In that context, Electron provides one of the best unified text-rendering stories of cross-platform options. But definitely far from the best overall.
But I wouldn't know first-hand.