> I use LibreOffice to open all my CSV files

I really love the preview, where you can choose what delimiters and character encoding you want to work with, which row to start from and so on. It's so very user friendly and nice to use.

It’s the best! I have no clue how Excel continues to be so awful at this, by contrast.

The Excel team treats the CSV format like Voldemort. They put no effort into it because it's an open file format they can't seize control of.

You should use Power Query for this usage, something like Get Data, From File, yada yada

I should double click on the file and it open correctly, like LibreOffice does when I set it as the default for this file type.

The problem is that Excel let you open a file with a random format. Same for LO, CSV data is usually so dirty that you shouldn't manage them without an proper loading process.

…but Excel already does it without a proper loading process and just breaks the files. LibreOffice figured this out. Just have a small modal that pops up when you open with sane defaults. This works the vast majority of the time.