It's definitely more than a gimmick. I understand why someone with no experience developing with Smalltalk might thing it's one - developers are used to claims of life changing IDEs that fall short.
Unfortunately, I've never found anything with an IDE that touches what you get in Smalltalk. I've always wanted someone to create an environment for Ruby, Python, or JavaScript that would give us the best of both worlds, depending on what you needed at the time. I remember attempts in the early 2000s, but nothing really touched it.
The only other language with an environment like Smalltalk that I've seen is Self, which is a prototype OOP language derived from Smalltalk, but that's even less popular.
Unfortunately, I've never found anything with an IDE that touches what you get in Smalltalk. I've always wanted someone to create an environment for Ruby, Python, or JavaScript that would give us the best of both worlds, depending on what you needed at the time. I remember attempts in the early 2000s, but nothing really touched it.
The only other language with an environment like Smalltalk that I've seen is Self, which is a prototype OOP language derived from Smalltalk, but that's even less popular.