It mostly has; most serious work is done in R and python, and there are a lot of supporting tools, documentation, and useful packages for both languages. It's not like the actual statistical analysis in your average paper was actually done in excel.
However, Excel remains a nice tool for "I'll just look at this CSV with the final results from this analysis, sort it by correlation, and see if any of the usual suspects are up top". And if the next step is "yeah, that looks fine - I'll just copy the top 100 genes into this convenient GUI pathway analysis tool", you're suddenly exposed to whatever Excel did to your data.
And as for "why not libreoffice", most researchers I personally run into are strong molecular biologists who've learned a subset of R for their uses; they're not really likely to go out and find libreoffice on their own. Besides, the writing process for papers includes sending drafts and spreadsheets to doctors and pathologists and editors, who are probably on hospital computers with a short whitelist of programs ... and I don't really want to debug subtle compatibility issues in the sort of garbage fire those documents can turn into.
However, Excel remains a nice tool for "I'll just look at this CSV with the final results from this analysis, sort it by correlation, and see if any of the usual suspects are up top". And if the next step is "yeah, that looks fine - I'll just copy the top 100 genes into this convenient GUI pathway analysis tool", you're suddenly exposed to whatever Excel did to your data.
And as for "why not libreoffice", most researchers I personally run into are strong molecular biologists who've learned a subset of R for their uses; they're not really likely to go out and find libreoffice on their own. Besides, the writing process for papers includes sending drafts and spreadsheets to doctors and pathologists and editors, who are probably on hospital computers with a short whitelist of programs ... and I don't really want to debug subtle compatibility issues in the sort of garbage fire those documents can turn into.