In my opinion, we definitely could omit "to pitch to" and the sentence would have the same meaning, in fewer words. It might also make sense to change "available" to "potential", but that would depend on the intended meaning.

You could change it to 'sell to' or 'advertise to'. 'Pitch to' has a slight sense of not telling the truth, which is what politicians do! Also by adding it, it suggests more active selling.

Is it necessary? Yes. Could you swap it for "customers to reach " ? Yes. It would convey the same meaning, but that doesn't mean that pitch to is exactly the same as reach. A pitch is a shortened form of "sales pitch." In this context, the word pitch is being borrowed from the sport of baseball where the pitch is the delivery. The pitcher delivers the ball to the batsman, just as the salesman or politician delivers a message to his audience.

In this context, "pitch to" means to try to convince, typically to buy something. When someone is trying to make you buy something, it is often called a "sales pitch". By itself, pitch can also just mean talk. But it isn't often used that way.