If I was to rewrite my blogpost to fit your second sentence I would title it: "Please consider onboarding new staff as a need for your software". This is just another consideration when architecting. I absolutely will use cutting edge tools if they are needed. But we just need to think about it a little.
Indeed the availability of developers who know the tech stack is a key requirement that should be defined and assigned an importance level.
And if you’re working in a business building a modern web application then it’s extremely hard to imagine the stakeholders being happy with software developed using absolute lowest common denominator tools techniques and libraries, as advocated by the “boring software” movement.
Competitive advantage and the expectations of customers leads to the need to use modern tools techniques and libraries.
And in fact developers deserve these things too because they tend to make things easier more powerful and more reliable.
If the stakeholder who is paying for the project says “can we have an animated user education intro”, and you say “no because we use boring technologies and our developers might not understand how to use the animation APIs” them I think your job would be at risk pretty quick.