Excel Formulas Limitations when compared to Excel VBA Power

Question

I'm an Excel VBA programmer that had to start learning how to create solutions with "pure" Excel (I mean, Excel Formulas only, not Macros allowed).

I have found that Excel Formulas are very powerful. I mean, you can:

1 - save your variables in cells;

2 - search for data in tables using Excel Lookup and Reference Functions;

3 - make If statements using Excel Logical Functions;

4 - make Loops using relative formulas reference (e.g. =RC[-2]+RC[-1]) up to 1048576 loops (max number of rows);

5 - deal with text, dates, and numbers using Excel Text Functions, Excel Date and Time Functions, and Excel Math Formulas;

6 - and so on...

I would like to ask for any simple problem that requires the power of VBA and sets the boundary limits of Excel Formulas.