This is not as much about Figma, which is big already and will be fine, but the 100 other potential Figmas that might not even been started yet. They will have more difficulty finding funding, attracting employees with equity, etc., when the scenario 'big tech co acquires company for lots of $' doesn't exist anymore.
Why would anyone go worth at a small company for equity if there's no chance to get liquidity? Why would investors invest? This decision might improve the short-term situation of the market, but over the long-term, I can only see how it benefits the big companies, which rely on today's cashflows / RSUs to attract people.