It has been a few years, but the last time I tried importing CSVs into both programs, LibreOffice had a much lower chance of mangling the data. Excel loves to be "helpful" which often resulted in turning lots of things that aren't dates into dates.
Same experience. If your main language has a decimal comma instead of decimal point, and you CSVs must use alternative delimiters, in my experience LibreOffice CSV importer is better.
Opening csv and importing data from csv are two completely different things in Excel