And there will never be competition. It cost Cirrus (small, single engine GA aircraft) $100 million to get a type certificate. The Boeing 737 max is still on its original type certificate.
Boeing and airbus is what the (western) world has for big jets. It's a duopoly and has no signs of not being one. Boeing probably shouldn't be a public company either.
The rest of world's aircraft manufacturers are quasi majority state owned enterprises.
The fact is there's no competition in the American commercial part 121 airline world. No competition makes you lazy and incompetent.