No mention of smalltalk? Essentially Objective-C was smalltalk message passing bolted onto C. Then you had Objective-C++ which allowed a whole new language rolled in. I still find myself writing MacOS apps in Objective-C/C++ which allows me to use all the fantastic C++ libraries and frameworks that exist. No doubt Swift is a better language that gives you strong typing and functional constructs, but I’ll always have a place in my heart for Objective-C.