The very young, the very old and other similar categories probably don't need to think about professional development. But everyone else should.
Why? Because of how loosely the word professional is bandied around. Lots of people think anyone who is self employed is "professional".
Anyone who can see the value in consistently identifying, specifying, designing and delivering the right product for the right price is already interested in professional development.
Why? Because that is one of the labels people apply to learning how to consistently identify, specify, design and deliver the right product for the right price.
In the trades, the learning process is called an apprenticeship. In Medicine it is called internship. In Law it is called a professional year and so on. At the end of each of those learning periods there is a formal assessment. The people who pass those assessments are allowed to call themselves professionals in those fields because an independent authority decreed they are.
The lesson to be learned here is: if you know the discipline of your profession, certification is straightforward.