I agree one would have a similar experience as the author when learning Flutter, but it is because on mobile you need to have all these shiny things so it's no wonder that documentation covers it in detail. However, you can perfectly write Flutter apps without animations, transitions and the like.
Yeah… in Dart, which nobody knows.
Or GDScript, Godot’s language, which nobody knows. This is my major barrier to even considering Godot right now. Perhaps once their Kotlin bindings are ready for production…
can we not use any other language for it, like C, Cpp, etc
There are plenty of bindings for Godot, of various quality[0].
Godot is changing their plugin system in a future version, which hopefully will make language support much easier.