The Law of Leaky Abstractions[1] strikes again!
1 https://www.joelonsoftware.com/2002/11/11/the-law-of-leaky-a...
1 https://www.joelonsoftware.com/2002/11/11/the-law-of-leaky-a...
Not to mention, the Y combinator is itself a low-level detail of how certain high-level functions (recursive functions) can be expressed in the formalism of the lambda calculus.