Not to give Boeing any slack but what 757 had it's door blown open? The only one I can find was DHL 757 which had its cargo door open during flight. Boeing had nothing to do with that incident as the plane originally left the factory as a passenger jet. Later in the aircraft's life it was converted into a freighter by Precision Conversions LLC. This wasn't even a door plug situation like with AS1282 as the conversion process preformed by Precision Conversions LLC requires cutting a rather large hole in the fuselage for the cargo door. The other thing is Boeing hasn't produced a 757 since 2004, any manufacturering defect thats made it twenty years before causing issues is pretty impressive.

Also bombardier currently only makes business jets. The closest plane bombardier has ever made to competing with Boeing was the C series however those jets were designed for regional flights which is a sector of the industry Boeing doesn't really compete in outside of the 737 max 7. On top of that because of shady deals bombardier orchestrated Boeing got very scared and lobbied the department of commerce to enact a 292% import tariff on the C series. Due to the tariffs Bombardier ended up completely selling the C series to airbus in 2020 who rebranded it to the A220.