Clearly, your examples do not account for many classes of applications such as software drivers or operating systems or automated theorem provers.

Yaron Minsky from Jane Street claims that they find Ocaml very productive in trading applications because of type checking, which allows to elimitane a lot of errors before they run the application. I don’t think they’d benefit from switching to Smalltalk, actually I’m convinced of the contrary.

My impression is that Smalltalk is a fine replacement for Java (or to be more accurate historically, that Java is a poor replacement for Smalltalk), and that it probably has no real competitors in the development of GUI applications.

But I also don’t think that “Smalltalk the language” is the key ingredient here. I rather think that it is “the Smalltalk philosophy” and “the Smalltalk development environment” that are crucial for its character.

I am curious if there are any books or other education materials that you could recommend for Smalltalk.