That's not true at all. Donations are the biggest source of income for The Document Foundation, the non-profit behind LibreOffice, and have been used to pay developers who've joined the team in recent years:
* Michael Weghorn (accessibility)
* Jonathan Clark (language and scripting support)
* Neil Roberts (scripting improvements)
* Dan Williams (macOS support and general UI improvements)
* Michael Weghorn (accessibility)
* Jonathan Clark (language and scripting support)
* Neil Roberts (scripting improvements)
* Dan Williams (macOS support and general UI improvements)