Are investors really that dumb?
SoFi would also feed investors both false information (as mentioned in the article), and inflated user growth numbers fueled by their freedom as a "startup" to spend insane amounts of money on customer acquisition with no regard for profitability.
Basically, SoFi spent all their money convincing people through advertising that they were "a new kind of finance company", all without actually creating anything new.
Turns out the company stops growing if you stop giving them money, and VCs didn't want to lose their $100 million commitment or admit that the company was DoA, so along came more rounds of funding.
There you go, that's the path to a $4 billion tech valuation with no actual tech product.