Yes and no. You may still need a media buyer marketing expert, but not pay out as much to brand a good name. Plus the marketing experts can't guarantee results but only guarantee their charge rates and Facebook makes a ton of money.
I can certainly tell you that is not how it works.
A good domain name is good to have but unless it is insurance.com or something so broad, you are going to need to spend money to generate real revenue.
Furthermore, we are talking about companies big enough to have someone on staff to do marketing.
And absolutely you can guarantee results... when a company is buying advertising, you are stipulating rates based on reach, conversion, or other metrics if you want to go that route
You need a good name and if you are happy staying small, spending money on a good domain works.
If you want to really grow however, you will spend A LOT of money on advertising.
It comes down to a simple equation...
If I spend X on advertising, will I generate more than X in return. As long as that equation is working, you keep pouring more and more and more into it.