I have not taught webdev folks C++, but I have taught brand-new C++ programmers just basic things for an intro course. I think it's easy to forget how hard it is to pick up for beginners except for the handful of people who have the ability to "think like the abstract machine".

I think folks who are steeped in the webdev stuff and UI don't always grok languages like C++ or its many footguns as easily as one may suspect. fwiw I feel the same way when I have to do any web stuff (i.e. out of my element). C++ may seem easy, especially when using a framework like Qt, but students tend to get really overwhelmed by all of the rules to avoid the language's pitfalls (e.g. the GSL rules, abseil's tips, Scott Meyer's books and so many other authors, etc).

Perhaps if one is a great teacher, the pedagogy can introduce these things in a tolerable progression. I found as long as students stuck to value semantics only they got it, but as soon as they used a framework that dealt in references / pointers it was a real step function in difficulty. Thinking about the lifetime pitfalls and related UB really ratcheted up the mental load, and I was not really trained how to teach effectively (like most grad students).