Anecdote: I have an Ionic app that is used by 15,000 people daily. It looks like a native app. Nobody ever wrote me an email that the app is not native, not fast enough or anything else. Normal people want to get their shit done and move on.
Heck, one user apparently was a dev and came up with a suggestion (enable keyboard suggestions for text input fields) and he wrote me specifically which iOS UI element I should choose over some other element he thought I was using. I replied: thanks, but this is an Ionic app, it doesn’t use native iOS elements ;)
Native apps are totally overrated imho, unless you make heavy use of fine-grained input controls. Here, Ionic does have its limits. You can’t control the keyboard properly for example, unless you wire in some Cordova plugins.
Oh and JS doesn’t run in the background. This can cause issues if you do a lot of background processing.
But performance is not much of an issue anymore in 2018 and Ionic is the most polished web-based framework that is tough to distinguish from native apps.