You don’t need to raise VC to build a business with big impact, even in a market that has heavily VC-funded players.
Excalidraw is an open source alternative to Miro. Excalidraw is bootstrapped and revenue-funded, Miro is VC-funded (476M raised).
Miro just added a comparison page to Excalidraw - meaning that they saw enough demand for people searching for Miro vs excalidraw that they added this page.