Oh boy!
Lack of proper table support.
FILTER is borked.
MAP functions and their ilk aren’t there.
The DBASE functions have serious issues.
Array formulas sort of work but often results in issues.
Calculation speed is super slow. I’ve tried converting a pension forecast tool and it just ran so incredibly slowly.
As someone self hosting my own Nextcloud with Collabora, I can tell you that living with LibreOffice is easy - but living with Libra Calc is impossible. It is not a workable, serious solution.