Uber, for example, could probably lay off 80% of its engineering staff and turn profitable if it was truly necessary. This would be stupid, because then they can't build new products (and thus compete) but they are default-alive [1].
The original author says that these companies "dump" stocks at IPO, but fails to recognize that (1) institutional investors who purchase most of the supply of stock at IPO are highly sophisticated and (2) there is a lot of regulation around proper disclosure of financials of public offerings.
Hell, the one recent tech company which tried to "dump" stock at IPO got laughed out of the public markets (WeWork).
I agree with the above poster that this article is nonsense and shows a complete misunderstanding of how markets and valuations work. Of course you would expect companies that are not profitable because they are investing in growth to lay off employees in tough times!