I loved Smalltalk but it was strictly a hobbyist language, I’ve never seen it in production code. I even purchased Smalltalk for OS/2 when OS/2 was on the way out.
But I did have one big issue with it: the required use of early returns. When I stopped using these in C / C++ my bug counts dropped to near zero. Not something I want to delve too deep into in a response but I’ve used three in 25 years and regard their profligate use as solid evidence I am reading the code of an immature developer.