Sure, nine is a lot, but your comment says "more than 1 font". Without arguing the semantics of what you meant by "font", hopefully using different font sizes and emphasis (bold/italics) do make sense to you. If those make sense, then using a different font entirely shouldn't be too complicated to see as a feature that an Excel user who's not using it for graphics design reasonably want.

Legibility is an important consideration, and with Excel, the size of sheets tend to grow until there are too many columns. So now you have the normal regular size font and you use a different font that's more legible at small sizes, especially when rotated 90.

There have been umpteen attempts to replace Excel. User interviews to understand how customers actually use the tool are important. Having the hubris to say customers are doing it wrong without even bothering to understand their use case is the first step to failing at replacing Excel.

Don't get me wrong, I cringe every time I fire up a spreadsheet and it grows past a reasonable size or length of use, or any number of shortcomings. Sometimes I even switch tools or write my own when that happens but lately I find Airtable's a pretty good replacement for most human (aka not finance) use of spreadsheets.