What you're describing there is typically the result of government-imposed regulations stifling free market competition, thus enabling the formation of monopolies (or oligopolies) that wouldn't naturally exist.
It's another example of how pointless government "jobs" cause immense harm.
Without the government interference that enables them, such monopolies/oligopolies simply wouldn't be able to survive, eliminating the problem you're worried about.
> Without the government interference that enables them, such monopolies/oligopolies simply wouldn't be able to survive
If you think market concentration is a product of regulation, then I don't think the economic world, or indeed the concept of government itself, is going to make much sense to you.
What interaction(s) have you personally had with government?
Do you personally depend on government for your income/existence (as your "job", via welfare, via tuition/scholarship, parent's/guardian's/partner's/supporter's "job(s)", etc.)?
It's another example of how pointless government "jobs" cause immense harm.
Without the government interference that enables them, such monopolies/oligopolies simply wouldn't be able to survive, eliminating the problem you're worried about.