Yes. I maintain some open source Mac apps in my spare time (and even develop new ones from time to time) using Objective-C. I've known and used this programming

Yes. I maintain some open source Mac apps in my spare time (and even develop new ones from time to time) using Objective-C. I've known and used this programming language for 20 years, and don't really see the point of investing in Swift given the way the Apple ecosystem has developed.