What? Prototyping is often the easiest and most fun part of projects. Often a prototype taking 1-2 people a few weeks turns into an entire team fleshing it out full over the next year or more. Thats a lot of risk if it goes wrong. Theres usually very little risk in prototypes going wrong, thats one of the main reasons to have a prototype phase to begin with.
You make one prototype in a few weeks with a couple of people then call it a day and start fleshing everything out???
Dude, it might take a few weeks to work out if a big project is even viable in a large company.
Prototyping a full product is not the easiest part of the big project by a long shot. Prototyping is when you find and create the constraints, reduce the chaos and make the project legible so other people can work on it.
If you do it right, it should make it easier for other people to work on the project not harder.
The older I get, and the more I work on aspects of trying to build businesses, products, and services, the more I lament the loss of a kind of service-oriented ethos that truly makes societies great and that seems to only be "refreshed" (in America, in particular) by the darkest of times*. Here, I think of the people who went through the first half of the 20th century in comparison to the MBAs and similarly naively "optimizing" agents elsewhere in important / controlling positions in current society.
Game theory 'says' that anyone can choose D(efect)-heavy strategies, and in many environments, profit heavily, personally (aka, "The only rules that really matter are these: what a man can do and what a man can't do..."). But, a society with too many such players is not long for this world.
* Much as was said by a certain Founder about the "tree of liberty" - many of the Founders, including even TJ, who could be quite self-interested, understood that liberty requires responsibility and sacrifice ...
How so? If anything it seems the opposite is true. (Prototyping, almost by definition, is almost zero risk. While bringing stuff to market requires real resources, and invokes actual brand and reputation risk. Might be different in some situations, depending on the resources required at respective stages, but that seems to be the long and short of it).