The maintainers of CocoaPods recently announced that they're stopping active work on it and they strongly encourage everyone to switch to Swift Package manager. They even directly addressed Flutter developers:

E.g. I maintain Unity, React Native, Flutter etc. A lot of these projects will (and should) be migrating to Swift Package Manager with time. As specified above, we are not breaking anything but bugs you may raise are unlikely to get fixed.

It seems that the Flutter team had been working on SwiftPM support for some time, and they clearly heard about the announcement. I even found docs targeted towards plugin authors:
https://docs.flutter.dev/packages-and-plugins/swift-package-manager/for-plugin-authors

I can't really judge the complexity or feasibility of this myself, but I can say that our CocoaPods release pipeline is broken yet again and I couldn't find a way to fix it on first try. Dropping support for CocoaPods from the SwiftSDK would be a great relief, so if there's any chance we can switch to SwiftPM, we should at least evaluate when & how this could be tackled.