Go has many shortcomings that make it difficult and extremely annoying to do refactorings. Things like no constructors where types are declared as follows

    A {
        Field1: field1,
        Field2, field2,
    }

Now adding a new field to A would require ensuring that all code paths initialize Field3, otherwise you're going to have silent errors at runtime. This has been solved ages ago in Java and C# and similar languages by means of constructors.

A constructor is just a function though... If I add a new field to a Java class and fail to add its initialization to the constructor, I have the exact same problem because Java initializes the field to its default value when the constructor is called.

You are correct that every situation where the struct in Go is initialized "bare" would need to be addressed if a field is added, but Go considers this a feature, not a bug (and, conversely, considers "bare initialization" of structs at dozens of places in your code to be bad practice if that struct could ever grow new fields). If you're bare-initializing structs, you're comfortable using them in a "loosey-goosey" context where zero-initialized fields are permitted (or, better, useful... https://www.youtube.com/watch?v=PAAkCSZUG1c&t=6m25s). In Go, the issue of required structure is addressed by wrapping the struct in an interface and then providing a function in the package that can create an instance of the interface. Used in that way, you get something very similar to a Java class (though Go doesn't force you into the "everything is a class" paradigm that Java demands).

> but Go considers this a feature, not a bug

I see this dismissive philosophy in golang a lot (I'm not saying you're doing it, mind you). The entire language is full of arbitrariness. I've seen enums being dismissed by the golang team just because, without providing any meaningful arguments. Same with how nullability was not addressed in the language, contrary to how proper modern languages have tacked the issue. The excuse? "that's how the underlying machine operates". Quite meaningless and dismissive really.

Time and time again, it's been shown that the goal is to have a simplistic (not simple) language that also makes it easy to write the compiler for. This breaks down at larger scales because reality is complicated.

Usually you would create a constructor without that parameter which sets the field to something backwards-compatible.

This perspective ignores the fact that there is no shortage of typed languages that don’t have all the—in 2021—inexcusable downsides of golang.

There is unfortunately a shortage, still in 2021, of languages that have a null set of inexcusable downsides.

I will trade - unhappily - ADTs for value types, automatic memory management, some language-level concurrency support, a compiler that builds our largest project in under two minutes, and a community large enough I can spend my time training new hires on fundamentals and business problems and not tool onboarding.

.NET Native, OCaml, Eiffel, Common Lisp, D, Nim just for starters.

Value types are almost there in Java, but without deliberately trashing the GC you can get away without them, and it has all the other qualities (and will have ADTs as well, sealed classes are already in preview)