How many Excel tabs are too many?

At what point does an estimating spreadsheet stop being a spreadsheet and become a software application? 😂

I've seen some pretty wild ones.

Multiple workbooks, 30+ tabs, macros, hidden sheets, pricing databases, formulas everywhere...

And then there's always one guy who says:

“Don't touch that cell.” 😂

Curious what everyone else is working with.

What's the most complicated Excel estimating setup you've seen or built yourself?