Edit: I posted a video about this topic here so you can go watch that if you do not like reading :)
“Most People” go on to learn to use programming languages and frameworks rather than learning the core concepts of how a particular platform (say the web) works. “They” do not go on to learn how code gets executed in a programming language they rather pay more attention to learn how to code.
I’ll support my opinion with an analogy to convince you - if you teach a person how to catch fish using a spear, the person would catch the fish and use the fish for nutrition but if you teach a person how exactly a spear works, or in other words, teach them the craft to use any weapon, the person would be able to feed himself for his whole life; even if the fish disappear, the person would be able to hunt other animals for food.
I'll also support my analogy with mathematics, as it is the only art that never lies, suppose a person takes 5 years' hard work to master the weapon craft and catches no fish what so ever in that time; on the contrary, a person who just knows how to "catch" fish would catch maybe 5 fish a day so the person would in total catch 9125 fish(5*365*5) in 5 years.
When the person who is a master of the craft would start to catch fish, I am pretty sure that he would be able to catch 1000 fish in a day, so as basic math says, the person would be able to catch 10000 fish(10*1000) in 10 days. This proves that a person who masters the core craft would earn more in 10 days than the normal person earns in 5 years. Also, that talent stays for ever, so you can catch a 1000 fish or chicken or crabs for the rest of your life everyday.
If you know the concepts well you can easily implement the system design easily in code. As very less people learn these concepts, it is an opportunity for you to become one of the top programmers in a niche.