Compose multiplatform is the future. I've used Flutter extensively but I created my first Compose Desktop app about 2 years ago and haven't looked back. Everything was alpha back then, and the tooling was only okay, but it is quite an impressive dev experience now, and there are two huge advantages over Flutter:
- it is truly native, in the sense I can directly talk to native APIs on each platform without going through bridging code and there's no special runtime
- Kotlin exists outside of Compose Multiplatform. I love Dart as a language, but the reality is it is irrelevant outside of Flutter. Due to Kotlin gaining some popularity across various platforms and domains, it has an advantage that people who already know the language will decide they want to try Compose Multiplatform, because it's low risk and low effort to try it out