Well, for a long time speed was not a priority at all for the team developing cpython. In fact, Python 3 was still a bit slower than Python 2 until a few versio

Well, for a long time speed was not a priority at all for the team developing cpython. In fact, Python 3 was still a bit slower than Python 2 until a few versions ago. Recently there have been some decent improvements to CPython's speed, but there are real upper limits to how fast you can make an interpreter. CPython will need JIT compilation if it is ever to break out of its current speed bracket. JavaScript has had a feature complete JIT reference implementation since 2008 which is a major part of the reason JS applications exploded so much in the 2010s.