Sure, functions and their composition are very often another highly useful abstraction that is easy to reason about and saves the programmer a lot of mental effort.

> We now have a chicken-egg problem.

No, just a recognition, which was not there in the original claim, that ifs and for loops are not the only useful abstractions.

> A programmer who, say, learned from SICP first would find a for loop awkward and bizarre when you could "just" tail-recurse.

Perhaps, but I think such a programmer who needed his code to be readable and understandable by a lot of other people in a large project would end up inventing a "for-loop" macro or something similar that, while it might use tail recursion under the hood, would express the construct in a way that programmers could understand regardless of how they learned programming.