The difference is where the majority of the "idle wealth" is created. Sure, there will be great business doing consulting work leveraging cloud providers - you can make a good business simply consulting on such things.
However in the end you're simply enriching a large company. Whenever an "amazon cloud consultant" transitions a closet of servers to AWS - they made a bit of money, but the large bulk of the value of that customer is now in a giant corporation's hands vs. being spread out how it was traditionally (either in house, or via much smaller infrastructure providers that generally competed on service without much lock-in).
The lack of competition in the web space is astounding to me, and will be incredibly damaging to innovation. How quickly people forget why decentralization used to be considered such an important goal. Yet it appears the entire industry is rushing head long into this model.
Startups then return to what they are in any other countries. Just a way to make a living rather than the potential path to riches it is in the bay area.
As a side effect you get smaller elites controlling more of the pie. That has other implications as well.
A valid concern, as pointed out, is when the large platform providers begin moving into domain-specific markets, leveraging their scale and closing out start-ups/small business. However, I believe nimbler startups will always be able to carve out a successful niche as long as they are closer to the customers.