No matter how much money is behind AEW, they aren't going to be able to compete in marketshare and mindspace with WWE. Ever. Nor is any company. WWE is NBA/NFL tier. Outside of a 2 year period, WWE is literally the only name in wrestling that has mattered to the American public for 35 years. WWE is literally synonmous with wrestling to the point where anytime you hear something on the local news about a fight or wrestling, it's referred to as WWE.
AEW could be competition in the sense that it might make WWE pay more for some talents, but no one will ever be able to compete with a company like WWE, which has been around and has had relationships established with arenas/owners/ticket companies/promoters/manufacturers/etc for going on 60 years. It will be good for talent for sure, and it might light a fire under Vince for a bit, but it will compete with WWE as much as AND1 and Big 3 compete with the NBA or Arena Football and XFL compete with the NFL.