While it can lead to more concise code as a dynamically typed language, JavaScript allows variable types to be determined at runtime and optimizes speed during runtime.
On the flip side, JavaScript, with the help of JIT compilation which converts JS code into optimized machine code at runtime, and event-driven architecture, which handles concurrent operations effectively without blocking the main thread, results in faster execution speeds compared to Python code. While it can lead to more concise code as a dynamically typed language, JavaScript allows variable types to be determined at runtime and optimizes speed during runtime.