There is a bit of chicken-and-egg here because as a former tech co-founder, i'd argue that much of the risk of entrepreneurship was ameliorated knowing a larger player could acquire you if you do well. I wonder whether -- if FB/etc were not allowed to acquire budding successful startups -- whether

0. Founders would take the risk

1. Early engineers would take the risk

2. Angels/VCs would invest as much in them

In which case you get fewer/none Instagrams/WhatsApps, because the risk is so much higher if your outcomes are limited to IPO/cashflow-business/lifestyle