I think that depends on what you take as a baseline for a non-expert. For the violinist you seem to take somebody who does not know how to play the violin at al

I think that depends on what you take as a baseline for a non-expert. For the violinist you seem to take somebody who does not know how to play the violin at all. For the cloud architect however, what do you use? A person who has never touched a computer? An average programmer/system architect? I'd argue that the time to cloud architecture expertise is far lower for the second than the first, and those things are older than 8 years.