That analogy may not be suitable for this case because value proposition between the aesthetics vs the function is different for visual art projects compared to software. There is also the maintainability factor where most aged software (especially the closed source ones in private sector) change maintainers every few years. Old maintainers most often lose access to the source code and become unreachable after leaving their job.
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.