What other programs can do what Excel does?

What are some other programs?
Office Suite Comparison at PC Mag

Why is Excel better or worse?

This is quite open-ended and very subjective. Excel is very mature, robust and widely used and is, effectively for the time being, the defacto business standard for spreadsheet applications.

Whether it is better or worse is subjective to personal requirements and experience as measured against use of competing products: if it does what you need, has all the funtionality/features you require, etc., then what more can one say?