My gut (informed by 30ish years of professional hardware and software engineering) says implemented at scale, on a real machine, we start seeing the same performance issues functional languages have where absolute conformity to the math will increase latency.

Tis why Haskell, etc, will not be used to write a meaningful OS wielded at scale. Graphics mutations don't want to wait for long dead Mr Euler or whoever to be satisfied.

Having to cache states as rigorous axiomatic rules are satisfied without C like ability to cut the queue and mutate some value just moves the problems C creates being able to do that, doesn't eliminate them; thermodynamics is a bitch like that.

Math is not physics. Physics is not math. Math is merely a syntax for notation of physics like how English is a notation for allegory and metaphor.

Physics is immutable and will not break because we decide some syntax suggests it will.