Smalltalk got a lot right very early on that got adopted in bits by everyone eventually. The idea of a fully interactive IDE, designing systems as distributed objects that exchange messages, and so on.
Unfortunately parceling it out and fudging it killed a great concept and we got stuck with corporate driven "OOP" that lives on in Java, Kubernetes, etc.
It's a wonder the people at PARC divined so much of great conceptual designs and other companies got to profit from bungled versions thereof.
Smalltalk is not perfect, it had some good ideas, but also some bad ones (in the sense of not being practical in most contexts) like the "image" mixing of code and data.
I did provide an alternative. Formally verify their software, making implausible for such error to occur. I have linked to a peer reviewed article that goes in-depth about such.
