Stating the obvious but the problems start when you pretend you're Amazon on 1/100000th of Amazon's budget, and you can't keep up with the costs and complexitie

Stating the obvious but the problems start when you pretend you're Amazon on 1/100000th of Amazon's budget, and you can't keep up with the costs and complexities of trying to be like them. The author's advice is probably derived from smaller-scale experience - not necessarily even startup work, just low-budget, small, inexperienced teams, etc.