Hopefully future us won’t look back at this deal as the beginning of a weak M&A market
Severely limiting the ability to be acquired reduces the incentives for new founders as well as investors in new companies if the only realistic path is waiting for them to go public. Especially since being acquired doesn't require you to be in nearly as good a financial position in terms of profit as going public does.
It’s a bit like asking in 2009 if the secondary mortgage market is a valuable market worth having. It provides significant good (IMO) to support real estate transactions.
But, I don't think that YouTube or Instagram are an inherent moral requirement for society, so I don't think it's the end of the world if they never existed.