There’s a wide difference between learning the semantics of an API and learning the semantics of a custom language with a compiler. There are alternate implementations of the React API, like Preact. The semantics of the React API might be complex, but you could implement them in essentially any programming language with function pointers and variable length arrays. You can’t say the same thing for Svelte; which we know is impossible to implement in pure JavaScript, which is why it needs a compiler. This is all anyone in this thread is arguing - it’s an argument about semantics but for some kinds of environments semantics are very important.
I’ve helped teams pilot out of own-the-world frameworks like Backbone and Rails before (both of which substantially distort the runtime they’re embedded in); but it was much harder to deal with Backbone + Coffeescript together. For Backbone w/ vanilla JS or Rails, we could use standard static analysis tools, Coffeescript added a big extra wrinkle to our migration.
I’ve helped teams pilot out of own-the-world frameworks like Backbone and Rails before (both of which substantially distort the runtime they’re embedded in); but it was much harder to deal with Backbone + Coffeescript together. For Backbone w/ vanilla JS or Rails, we could use standard static analysis tools, Coffeescript added a big extra wrinkle to our migration.