True, but while CPython does have a reputation for slow startup, completely re-implementing isn't the only way to work around it - e.g. with eryx [1] I've managed to pre-initialize and snapshots the Wasm and pre-compile it, to get real CPython starting in ~15ms, without compromising on language features. It's doable!

[1] https://github.com/eryx-org/eryx

Speed is not a feature if there isn't even syntax parity with CPython.