We've all heard of startups that accomplish these huge goals and in most cases did what large companies have tried and failed. Why is this? Most startups don't have any money or resources. They're just running with a dream. So how effective can a dream be? How come the larger companies cannot accomplish these goals when they have all the resources?
Not all startups are wildly successful. We only hear about the ones that are. But startups are more productive, for various reasons. The biggest key to a successful startup and any company is the people and freedom to be efficient. Startups typically have very small management structures. The communication process is streamlined. Any development team with vast knowledge and determination can do amazing things. You just need to give them direction and turn them loose. Startups kind of create this "perfect storm" where you have 5 super determined geeks who want to get something done quickly. They don't need to do the mundane tasks of recording their time, writing developer documents, discussing change processes, etc. The reason is because none of that is in their goal. Their goal is to finish the project quickly.
Startups and companies are not apples to apples
Startups have the luxury of not having people who've been there for years. That save time, because now the process is being designed as you go. Nothings more frustrating than learning a process that offers no value but is "they way we've always done it".
Startups have people who WANT to be there. They just want to code like a mad man and hopefully get paid at the end. The startup is a stepping stone, not a destination. Because if the startup is successful, then it slows down and turns into a company.
No legacy problems. Everything is entirely new, so the only problems you have are the ones you create.
Startups are entirely evolved around quick turnaround. You need to get your project done to get paid. And you need to get it to market faster than the other guy.
My advice for companies
Mix and match. Find what works for you. Don't make your developers write docs, it's unproductive and the business requirements should do that anyway! Don't be afraid to try something different. It could make your life easier and more productive. Remember, every process has room for improvement. And please, PROTOTYPE, PROTOTYPE, PROTOTYPE! This concept works and is quick to market. Over the 13 years at my company, I've done around 30 prototypes, and we're using them all in production today.