Well, auto looks just like var in that regard.

It really isn't. Neither in C# nor in Java. They are just syntactic sugar to avoid redundant type specifications. I mean things like Foo foo = new Foo();. Who gets confused with that?

Why do you think IDEs are able to tell which type a variable is?

Even C# takes a step further and allows developer to omit the constructor with their target-typed new expressions. No one is whining about dynamic types just because the language let's you instantiate an object with Foo foo = new();.