That last sentence is worryingly close to conspiracy theory territory. There is no unified ‘They’ controlling what gets built in your town. Different places have different reasons for different things to be built. If you are seeing gas stations, it’s because someone with access to money, or pseudo-money in the form of debt, thinks they can make more money by building a gas station.
Chain A coming up directly across from Chain B might be one company trying to take over the area from the other. It could be Chain A management stupidly thinking 'we made $1,000,000 from our station at 5th and B, so if we open another at 6th and C it will also make $1,000,000. It could be upper management telling them to spin up more locations so they can go into next quarters investor meetings and say ‘Pay no attention to the debt on our balance sheet. Pay attention to the fact we just built 1000 new locations! We’re expanding! Please value our stock higher!’ It could even just be money laundering, criminals paying themselves $2 for every $1 of construction they do and then running the business pretending to sell gas for $8/gal. The one thing you can be assured of is, absolutely no one is sincerely saying ‘People need more banks and gas stations.’ The kind of person/organisation that spins up a dozen gas stations does not care what people/society need(s), only what they can do to convince people to give them more money.