Are we gonna accept being forever locked in to Microsoft because of custom Excel workbook formulas? Forever paying Microsoft a license fee, because we don't want to covert said formulas or invest in open source software to make it reach parity with Excel.
In many organizations, that license costs less than converting all the Excel workbooks - a process that disrupts work, as only the Excel spreadsheet's creator and user can reliably spec and test the new spreadsheet. And they need to convert with accuracy - worse than crashes is undetected bad output.
Being stuck in legacy systems sucks, and technical people like to deny the reality of it - but it's a business reality.
The problem with this is that the decisionmakers fucked up 10-20 years ago, and now when those decisions are being righted, some poor public servant is paying the price.