Netflix started in the original dot-com bubble as a DVD rental service, and only began streaming in 2007, a decade after they were founded. Reed Hastings put up $2.5 million himself. Not exactly a case of rapid illusory hypergrowth like the poster children unicorns of the current gig/sharing economy dot-com bubble.

None of these companies had to deal with the current investment environment. It's an arms race. While it's a chicken and the egg issue since both Facebook and Google provide virality and discovery, respectively, and it is those two features, virality and discovery that lead to a positive return on investment from blitzscaling.

Besides discovery and virality, there is also the issue of falling transaction costs. When Google, Facebook and Amazon were founded, you had to maintain your own datacenters and infrastructure. That alone produced a massive barrier to entry that made competition less fierce. Since the advent of AWS and other cloud computing platforms, transactions costs for tech companies have dropped dramatically so you can't rely on infrastructure prowess as a competitive advantage for many tech verticals.

You simply can't compare companies that were born and matured in different markets with different dynamics to those founded in the past 10-15 years. It's apples and oranges.

How’s that working out for them? Name one tech company founded since Facebook that has been massively successful - ie massively profitable.

Becoming a massively profitable megacorp isn't the only winning formula.

Were Linkedin, Instagram, Beats by Dre, WhatsApp, Tableau, Skype, GitHub, MuleSoft all failures because they were acquired for billions, making lucrative paydays for their founders and investors?

You missed the other part of the equation. No one said that all VC money was dumb. The conversation is about billions of funding going down the drain like in the case of Uber compared to the paltry sum inflation adjusted raised by the tech behemoths before they went public and became profitable.

Beats by Dre raised less than $1 billion in funding.

https://www.crunchbase.com/organization/beats-by-dr-dre

WhatsApp raised less than $70 million.

https://www.crunchbase.com/organization/whatsapp#section-ove...

From looking at Crunchbase, Instagram didn’t raise any outside funding.

None of the companies you listed raised anywhere near what Uber, Lyft and AirBnb raised.

That might be because none of these companies are operating in the real world while Uber, Lyft and AirBnB do.