I'm not sure it matters for most practical uses what i++ means so long as you know it is required.
Much as with {} being used for scoping.
Though I agree it is jarring how little many in Gen Z know about how anything works.
I've worked with GenX'ers and Millenials (I'm a millenial), and this isn't unique to GenZ at all. A large number of people don't understand, and are just getting by. Anecdotally, I've seen people at very senior engineering positions who just don't understand the basics of what they're doing. Does that mean that it's jarring how many GenX'ers don't understand?
My older relatives pore out the most excruciating details of their personal lives on people's Facebook profiles, not understanding that it's not a private message. These people grew up and we're the ones who warned us "never use your real name online", etc.
Again, can they quickly understand and apply the knowledge once it is explained to them is all that matters.
In reality it's honestly just better in 99% of situations.
increment operators are a language design antipattern anyway, not some fundamental knowledge.