From an engineering perspective, it's a solved task. Designing an airplane is on par with designing a suspension bridge.
From a regulatory perspective, the layers of bureaucracy needed to get approval to build a bridge has nothing on starting up an airline manufacturing company. Once you have a company with a history of approval, you can practically do what you want, but getting to that point is nearly impossible.
The difference is that there establishment space launch companies were basically monopolies using ancient technology and processes. That’s not true for commercial aviation, which is subject to pretty relentless cost pressures.
Seems like that’s what a lot of people say about a lot of legacy businesses though when facing pressure from a startup. Obviously doesn’t always work, but sometimes!
Bullshit i cant hear you. Commcercial airliners are sold at a loss and are basically giant jobs programs. Modern jetliners are enormously efficient already; there has been a continuous race over the last century to this end.