Your comparison of Bombardier is a good one - but not so much for you. Bombardier was losing money on the A220 nee C Series and was going to lose more even without the ITC decisions. They had no manufacturing scale and didn't have the money to build it - those A220s are now being built in Mobile, Alabama, alongside the rest of the A320 family.

Their order book was relatively thin - Delta took a big gamble in exchange for the hefty discount that those planes would ever get built. It didn't look like it. Canada and Quebec already had two massive bailouts for bombardier, owned a big chunk of the program, and said they weren’t going to put more in.

That program had massive cost overruns and practically bankrupted all of Bombardier. They only survived because of Airbus. Before Airbus, the Federal Government and the Quebec Government already owned 50% of the C Series project. Because of the C Series, Bombardier is a shell of itself - they sold off all of their commercial plane operations (the CRJ, to Mitsubishi, who subsequently cancelled the whole thing), they sold off all their rail operations to Alstom. They only build business jets now.

It was also a massive strategic failure for Boeing - who could have bought the program instead, and been selling a fantastic small plane instead of Airbus.

But who else has tried to build a plane? How is the Sukhoi Superjet doing? How about the Mitsubishi SpaceJet?

China will eventually be able to build planes with their own engines - but that's only thanks to truly massive state resources, and a big dose of corporate espionage. And it still will probably be a commercial failure.

Because building commercial success in the airline industry is hard. The old adage of "how do you become a millionaire? Start with a billion dollars and buy an airline" applies to almost every part of the entire sector.

You can't sell a few planes and make money to build a bigger plane anymore. You have to invest tens/hundreds of billions of dollars and bet on long term success - and there aren't many people willing or able to make those bets, for the next pandemic, recession or 9/11 to kill your business even if you did everything else right.

Airbus was propped up for decades by the governments of Europe, Boeing too - and same with Embraer and Bombardier. But even the resources of small nation states aren't enough to compete with Boeing and Airbus on their turf. Canada didn't have pockets deep enough for it - and they're a reasonably wealthy country.

Because Boeing is a massive military contractor. The US government needs Boeing, and will protect them.