In no world is a startup going to unseat Apple, Amazon, or Microsoft. Google and Facebook maybe.
VCs don’t want to touch hardware with a ten foot pole (Apple), competing with Amazon would be a money sink to duplicate all of the infrastructure as would Microsoft (who cares about desktop operating systems and the enterprise will never leave MS).
Acquisitions are one way to make money off big tech. Breaking them up and buying parts of them for cents on the dollar are another, especially if you can issue barely veiled threats of government-backed retaliation if they refuse to come to the table with your allies/fronts. With a "loosened regulations" regime, IPOs may be even more profitable than acquisitions.
There is very little chance that a startup will IPO especially now that the public markets have gotten wise to the VC funded Ponzi scheme where they treat the public market as the bigger fool
The latter half aren’t going to be buying stocks at IPO
Of course, that's exactly the pattern of behavior that is seen as problematic.