Yes, I completely agree with slow performance of Ionic. At my last job we used Ionic and the result was slow, sluggish app. I write my apps in iOS native Objective-C and Swift so I can clearly see the difference.
I think Ionic or Hybrid frameworks will be huge in the future because they save money and to be honest big companies don’t really care about the look and feel. Think oil and energy companies.
I read that Facebook has a weird legal agreement and copyright stuff when using React Native which illustrates that they have the rights to sue you whenever they want based on the API’s they are providing etc.