While my example is a relatively simple use of COUNTIF, you can use the function to check entire worksheets or workbooks. You can access Python in Excel ... just how much the software can do. I'm sure ...

Back in 2020, Reddit user /u/KrakenOfLakeZurich created a Sudoku solver in Microsoft Excel. It only uses formulae and conditional formatting, and it's available for both Excel and LibreOffice Calc.