To me it's mainly the following three reasons, but take it with a grain of salt since my JS is not as fluent as Python.

1. the async nature of JS is surprisingly detrimental when writing scraping script. It's hard to describe, but it makes have a mental image of the whole code base or workflow harder. Writing mostly sync code and only use things like ThreadPoolExecutor (not even Threading directly) when necessary has been much easier for me to write clean, easy-to-maintain code.

2. I really don't like the syntax of loops or iterations in JS, and there are a lot of them in web scraping.

3. String processing and/or data re-shaping feels harder in JS. The built-in functions often feel unintuitive.