Reasons why (supposition, not necessarily in agreement, just arguments I am familiar with) -
It's because foundations are now free but nobody understands how they work anymore - or soon won't hence the waning as opposed to disappeared. There are whole levels that a coder needed to understand in the past that recent entrants to the field do not understand, that can still subtly affect how things work, if no one understands the things the craft depends on, then the craft is waning.
For anyone who started programming more than 13 years ago in the most widespread programming discipline for the past few decades (Web technologies), which in this career makes you super-old, the craft is waning because every year it becomes more and more difficult to understand the whole stack that the web depends on. Not even considering the whole stack of technologies that my first paragraph alluded to.
For Frontend coders it is waning because there are ever increasing difficulties to find out how to do something someone else did by looking at their code - modern build technologies means looking at the code of a site is not worthwhile. And people were already complaining about that 13+ years ago.
If you have kids or outside work responsibilities then in combination with this and the need to produce things and the ever increasing eating of stuff by software (opening new problems and business areas one might need to be cognizant of) it becomes less possible, for those not in school, to hone their craft via purposeful working. For this reason it may be that the craft is waning.
Finally improving productivity is not necessarily something that correlates with improving the craft - industrialization may have improved productivity and made many products available to many people that did not have them before, but it is pretty well known that it was not beneficial to the crafts. Perhaps the feeling is the same here.