Not neccesarily? If you start with an Android app, the sentiment tends to go both ways. There's simply no good cross-platform mobile toolkits.
React Native and Flutter is fine if you want to do information app (backed by a backend for most of the work), but as soon as you want to tap into the native capabilities of the device, the difference can become too much. Those toolkits rely on being able to find a common ground between the two ecosystems, and sometimes that can be a hindrance.