The system is deliberately structured to spread money around, which works in favor of new and small businesses:
Awards, justifications, and even debriefs are public, so decisions have to be documented and defensible.
Bid questionnaires ask whether you have an active contract or recent awards, and when other factors are equal, they favor vendors without them — the government intentionally distributes awards.
Set-aside rules reserve slices of budgets for small and disadvantaged businesses.
Local and state contracts effectively belong to businesses registered in that area; an out-of-area company cannot simply come take them.
Incumbent vendors cannot hold the same contract forever — contracts regularly rotate back onto the open market.
None of this hands you contracts, but it means a properly registered, well-prepared newcomer is competing in a system designed to give them a real shot — the opposite of the private sector, where lack of prior customers works against you.