This is a very useful project for me, because I occasionally need real Excel.
I actually think a lot of people cared enough to do this; the entire Wine project sort of exists specifically because people want Windows software on Linux.
I know multiple people who have said that they won't use Linux specifically because it doesn't have the full-fat desktop version Office on there.
"Unnecessary"? Sure, I guess, I don't like MS Office and I don't use it, but a lot of people seem to really like it, whether or not they should.
If this were a proof of concept and you had the ability to say what you did different to make it work better than previous attempts that would be great, but i don't think you know.
I'm not entirely sure what your point is though? Are you suggesting I don't know how to write software? I've been doing this for a very long time, well before generative AI.