Yes, Excel really is a good product. But there are a few things people do consistently complain about with it in my experience:

- lack of forwards compatibility. When someone sends you an Excel 2016 file and you’re stuck on Excel 2013 because your corporate hasn’t upgraded yet, it’s a total PITA.

- weird bugs. Sometimes spreadsheets can get corrupted in weird ways so that they crash Excel and there’s nothing you can do about it and no way to fix it. Sometimes these bugs only appear on certain versions of Excel

- lack of decent built in formula tracing (ie something which brings up a dialogue and you can click through each reference in a formula browsing back and forth and going up and down the dependency tree). There are a few third party add one that do this but it really should be built in.

- lack of a decent way to see what’s changed between two versions of a spreadsheet

I’d also say there’s an inordinate amount of abusing Excel to do database tasks out there. People have spreadsheets which take minutes to recalculate which could be done in less than a second even using Access, let alone a ‘proper’ DB.