It is meant to be a new version of Cordova, with support for Cordova plugins. At this time the general consensus is that Cordova is still generally the best, unless you specifically need functionality in Capacitor.
These days it's mostly still just "use Cordova/PhoneGap", yeah.
For Flappy Royale (http://flappyroyale.io, https://github.com/flappy-royale/flappy-royale) we built our own native web view wrappers for both iOS and Android, but that's mostly because we already had extensive native iOS/Android dev experience ourselves and wanted more control.
In my experience Cordova/PhoneGap come with a lot of cruft and bloat if all you care about is a canvas and a handful of other hyper-specific native API hooks. At least in the sense of engineering and tooling complexity; I can't speak to runtime performance considerations, except that it should be irrelevant on iOS since everything's using the same WKWebView under the hood.
It seems the OP uses NW.js/Electron to target desktop, but I can’t see that they target mobile yet. Curious to know how they’d do this if needed.