Flutter is easier if you have previous experience with any kind of software programming.
In Flutter, you can do both iOS and Android applications. So, it is easier to use compared to Swift, Objective-C, Kotlin, or Java to develop applications. But, the popularity and demand of native apps written in Swift, Objective-C, Kotlin, or Java is more compared to Flutter.
So, It is better to learn Flutter afterward. Speaking in broad terms, it is not so difficult because it is SDK and not a programming language. So, Flutter is not a problem for most software developers
You can watch this video on Kotlin vs Flutter to understand more:
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