I'd like to believe you but some of the beefs I have are not edge case at all.
Top of my head, a few examples (in addition of the index/match):
1. the fx "Insert function" window, with a search feature that just doesn't work, a listbox that shows only 7 results and is not resizable (when the built-in functions alone is a huge list, plus all custom udf). Same thing for the Function Arguments window.
2. excel incapable of preserving the default for calculation mode (automatic/manual) between sessions
3. excel recalculating the whole sessions when opening a csv file even when calcs are on manual
4. terrible default formats (serious people don't want thick lines, 3d charts and all that crap)
5. Recent regression: can't copy a table from excel to powerpoint while preserving the format, formatting a table in powerpoint is a pain in the butt, default format are just bad
6. No way to link a powerpoint to a spreadsheet. Think all the bankers, consultants, engineers, who must present the result of some analysis, the data is in excel, the deliverable is a powerpoint deck, how do you link the two. Only ways I know are awefully manual and/or unstable and/or result in tables displayed as images in powerpoint
7. VBA not developped or improved since the late 90s (there was an interesting attempt at one point, VSTA, but it was canned)
I could go into more edge case things but these are mass usage features.