I’m cherry picking but A vs CNAME is incredibly simple, just not something most keep in their mind since you usually set it and forget it. As an aside, my guess is the recall rate would be a lot higher amongst people if the record types had better names instead of “A” and “CNAME”. Something like “Name-to-ip” and “Name-to-name” seem to be far better (I’m sure I’m missing nuance, like what do we call ALIAS, etc. but you get the point).
I guess to your core point I’m ok with there being different levels of engineers. Like any field once it becomes large enough there are opportunities for the deeply technical polymaths, the superficial tradesmen, and everyone in between. It’s just important that whoever’s hiring identify which level they want and hire accordingly. I’ve met plenty of people of both varieties so it’s not like the true “masters” of tech are dying out.
When people say "they don't know the difference between an A and a CNAME" they're not just talking about the basic definition of these concepts, which I agree with you is trivial.
But can you remember _which is which_? For instance, can a host have two A records? Can a host have two CNAMES? one of these might mess with mail delivery but the other is pretty common. Do you remember which is which?
DNS is an onion. At first it makes tons of sense. Then you learn a little bit and it makes less sense. Then you learn some more and it makes more sense. It is a bit tricky like that in a way that trips up lots of people. This speaks a little bit to your "levels of engineers," I think.
I guess to your core point I’m ok with there being different levels of engineers. Like any field once it becomes large enough there are opportunities for the deeply technical polymaths, the superficial tradesmen, and everyone in between. It’s just important that whoever’s hiring identify which level they want and hire accordingly. I’ve met plenty of people of both varieties so it’s not like the true “masters” of tech are dying out.