At any rate none of this "sugar" was a problem to anyone I know who learned Scala. There are harder things about it than learning basic syntax.
That problem does lessen with familiarity, but knowing a lot of complexity makes me wary of unknown complexities. It adds an overhead which takes energy that could be better utilised elsewhere.
But Scala's syntax and language features are great when you actually make use of them to accomplish your goals, especially so with Scala 3. The syntax isn't excessive or frivolous or nonintuitive. It's a pretty straightforward encoding of the desired feature set of the language.
If you want to make any object `foo` callable with first-class application syntax, i.e. `foo(bar)`, you add an `apply` method to that `foo`. You don't need to bother extending Function, you don't need to come up with a method name and call that. When you call `foo()`, you don't know if `foo` is a function or an object, and you don't care. You can find out easily with a half decent editor of course, but the point is, you're free to mix objects and functions as you wish, the language does not get in your way.
And for all that it provides, it's a complete non-issue in terms of learning curve. It's a basic language feature that you learn once and are never impeded by thereafter.