I will abandon Kotlin!
Microsoft recently released their Blazor WASM infrastructure that allows you to develop state of the art SPA / PWA s in C# and vanilla HTML. It includes Bootstrap binding for UI design, a mechanism to use legacy JS code and allows distribution as standalone folder (server less).
The tool chain is mature, support for multi platform popular VS Code and good ol’ VS.
The Apps are true multi platform due to .net Core that run even on ARM (RAS PI) if needed.
Ok, C# is more verbose and less modern than Kotlin but(!) it has an excellent infrastructure and support and Blazor makes a game changer for PWA development.