True, there is the "old maintainer" aspect, that differs.

But what exactly does this mean in relation that what are special forms in other languages are function calls in Rye?

Is the problem that you somebody could make their own control-structure-like functions? All these function calls have exactly the same evaluation rules, which is not something you can say about "special forms" in "normal" languages because special forms are exactly rules that break the regular evaluation rules.

Rye already has a lot of control-structure-like functions in it's standard library and many other functions that accept blocks of code and aren't related to control-structures. Yes, a "stupid" person can write "stupid" code in Rye, but you don't need much flexibility in any language to write stupid code.

I fully admit there are languages that are more suited for teams, and languages that are more suited for solo developers, for this reason.

That was also my point mentioning "million pixel website" because that "art" is directionless and crowdsourced and a painter can use the same pixels or even more flexible options to create beautiful images.