Advantages & disadvantages of automatically concatenating global css into a single .css

[xzilja]

I was glancing through css documentation for global css https://nextjs.org/docs/basic-features/built-in-css-support#adding-a-global-stylesheet and there is a section there mentioning following:

In production, all CSS files will be automatically concatenated into a single minified .css file.

I wanted to start discussion and ask why this is done, as I was under assumption that due to http2 it is better to keep them split into more files. Or is my assumption wrong and for css it makes sense to keep it as one file?

Also, I wanted to check if we already have some sort of setting that can disable this and keep css files as separate, if not, should this be considered?