Simplicity: Holes and Side Effects

"Eventually, in practice, almost nobody will be writing Simplicity code at all. Simplicity provides a well-defined foundation for blockchain programs, but it is just that: a foundation. The real work will be done in higher-level languages, which compile down to Simplicity code alongside proofs of their correct operation."

https://www.nobsbitcoin.com/simplicity-holes-and-side-effects/