No, they aren't. They are the same as languages from 40 years ago: We have had channels, coroutines, and good garbage collectors from long, long ago. Plus the syntax is directly borrowed from Algol 68 (from 1968).
Go looks nice because it fills a niche (a high performance garbage collected language that is easier to learn than Java and provides faster compilation times than C++), but there's absolutely nothing different here.
For "pretty different from mainstream" see Forth, Prolog, Erlang, etc.
Go only appeared about 10 years ago. The industry standard is 50 lines of production code a day. 50/day * 250 working days a year = 12.5k loc/year. So it would take you how many continuous years to write 200k LOC?
The industry standard is probably very heavily biased by big corporate code bases where refactoring / architecture takes a lot more time than implementing the actual changes afterwards. Doesn't seem like a very useful calculation you are trying to do there to proof the previous poster wrong.
I have a lot of time playing ms flight sim and so obviously I know how to design airplanes is his argument.
Writing "greenfield" applications that no one (comparatively) is using is relatively easy. Creating systems that have four+ 9's availability, integrate with various disparate APIs, don't lose data, and,and etc is where, IMO, the learning is.
Once one has this experience, watching this micro services "movement" is, in my mind, related to global warming - like watching someone jump out of a plane with no parachute, smiling.
Go has its benefits and reasons to use it (especially the network effects around it). But when it comes to the three things I mention, Go is truly pathetic compared to a language like Haskell. It's amazing how much effort is wasted on those activities. I can see why a corporation would not care, but as an engineer I can do better with my time and effort for my personally-owned endeavors.
Go is made to treat people as Resources. Full stop. That explains everything about it's benefits.
A bigger issue, IMO, is that people coming to Go from other languages expect it to have similar features to what they're used to. Go is small and conceptually simple, but its ideas and philosophy are pretty different from most mainstream languages.