The real reason for the popularity of synthesizers is cost. When you
need a new rock for every band they get costly, but a synthesizer
doesn't. This wasn't practical until chips that could do most of the
work became cheap.

The main reason for eliminating the commercial operator licenses was
cost too. Here's what happened:

There was a time, not so long ago, when there were a large number of
tasks that could only be performed (legally, anyway) by a person with
an FCC Commercial Operator license. No others need apply, regardless
of experience, education or background. Either you were a Radio
Operator of a certain class, or you weren't.

Those licenses meant that a person with a high-school education and
some smarts could have a good middle-class income if they had the
license. Not that all the jobs were easy, or that you didn't need a
certain amount of knowledge to do them, but that the Commercial
license became the equivalent of a union card, and the jobs were, in a
way, protected by FCC regulations.

In other words, the Commercial licenses protected a craft known as
Radio Operators, with a set of skills and knowledge specific to them,
and jobs only they could do.

The masters of industry didn't like that, so they prevailed on the FCC
to reduce the requirements and eliminate most of the licenses and the
requirements for tasks to be done only by Radio Operators. The jobs
went with them.

This is also why the maritime services went to satellite-based comms
rather than HF and MF radio and Morse Code - it eliminated the need
for ships to carry licensed Radio Operators.

Oddly enough, FCC still issues Commercial RadioTelegraph licenses,
both First and Second Class, though I don't know where in the USA you
can get the required experience for a First Class.

73 de Jim, N2EY