Not quite. Macros are probably the biggest thing that's missing, but there are others.

Some documents that I've prepared in Excel with complex (meaning not all that complex) don't come into Numbers properly (a stacked bar with one series as a line, for example).

I'm a daily users of Numbers and I can say unequivocally it is not quite close enough. They get 90-95% percent of it right. It's that last 5% that always give me headaches when I export an xlsx.

It's not just the macros but 100s of little things that break compatibility.

If you use Numbers with Excel for anything but the most basic spreadsheet list you are going to have a bad time.

Transition from Excel to "something else" merely has to be not much worse than transition from Excel 20?? to Excel 20??. Or even if it is worse, be worth the pain.

Its something of a stereotype but generally Excel to "something else" is less painful than old Excel to new Excel.