The "one of the greatest inventions in computing" framing holds up when you look at what it actually did to financial math accessibility.
I've been implementing the functions Lotus 1-2-3 made mainstream as a REST API — amortization, NPV, IRR, compound interest — and the formulas are completely unchanged from 1983. Forty years of software evolution and the computation at the bottom has been stable the entire time.
What changed is only the interface layer: mainframe COBOL → Lotus cells → Excel formulas → Python libraries → REST endpoints. The spreadsheet era was the step that made financial math legible to non-programmers. Everything since has just been a different packaging of the same numbers.
Excel on Mac has been closing the gap, but VBA macros from Windows colleagues still break regularly — sometimes silently, sometimes loudly. A workbook that runs perfectly on Windows will open on Mac and just do nothing, with no error. I've ended up keeping a Windows machine running purely because of macro-dependent spreadsheets.
QuickBooks is the more frustrating one. Intuit has historically treated the Mac version as a feature-lagged port — payroll features, industry-specific reports, and bank reconciliation behaviour all differ between platforms. The company essentially wrote the same product twice and kept them deliberately out of sync. Muscle memory from one doesn't transfer to the other.
The only partial escape I've found is pushing financial calculations out to platform-neutral layers entirely — whether that's a shared Google Sheet, a web-based tool, or an API. The moment the logic lives in a .xlsm file, you're platform-dependent again.