Anyone trying to unseat Excel is going to have the same problems as people trying to unseat Facebook: they already have lock-in of the vast majority of the userbase.
I use Google Sheets for most spreadsheet work now, but I was never heavily invested in Excel. Everyone I know who is a serious Excel user just isn't interested in anything else. Excel does everything they need it to do, and they have years worth of templates and formulas developed for all their needs.
Excel is also extremely robust. You can, for example, do VLOOKUP between tables that are ~10K columns by 100K rows. And it just does it. And pauses/restarts calculating, if you need to tweak something. But Calc? It just freezes, and eventually dies, and then must rebuild the file after restart. Which may end up being impossible. Indeed, Excel will do pivot tables that choke MySQL :) And it uses multiple processors.
Yeah. I've tried messing with those too. No luck. Calc seems to crap out at about 10 MB. Anything over 5 MB is prone to freezing. Especially if you use AutoFilter.
The first time I encountered the file-repair prompt, it was total déjà vu to the DOS era ;)
I use Google Sheets for most spreadsheet work now, but I was never heavily invested in Excel. Everyone I know who is a serious Excel user just isn't interested in anything else. Excel does everything they need it to do, and they have years worth of templates and formulas developed for all their needs.