There are plenty of choices for Small and Medium size plane as well as private jet. Why are most commercial airline only buying Boeing and Airbus? And why others aren't making bigger planes to compete?
Since topic is tankers, PRC/RU has their own tankers, i.e. for military aviation it's not strictly as difficult since fuel cost less issue. But for strategic aviation (transport/tanking) big efficiency working with commercial chassis / turbofan efficiency.
Neither Boeing nor Airbus make their own engines. They get them from CFM, GE, Rolls-Royce. Like everyone else. That's not the differentiator.
But it just costs insanely much to get an airliner certified. Even Boeing has been held back by its clients demanding a shared type certificate for the 737max which caused all those deaths due to mcas.
There were of course more players but they've been bought up. And some emerging brands that are excluded from our markets due to sanctions like the Chinese Comac and the Sukhoi Superjet. The superjet is particularly affected because some of its systems were designed by western companies like Honeywell and they've had to make last-minute replacements after the Ukraine war that didn't exactly work out well.
And there's some other players. Embraer is creeping closer to the 737/A320 market.
But anyway so it isn't just Airbus and Boeing really.
It's differentiator in sense engine manufactures are part of western aviation industrial complex and can limit access, i.e. COMAC sanctions. Unless you're western core, you do not have guaranteed access. I think Embraer is creeping on to bottom end of narrowbody, but they're far from wide body. And with respect to topic, modern strategic tanking are wide body size, i.e. Embraer E190 is not same heavy league as KC46, MRTT, Y20, Il-78, and Embraer has not demonstrated ability to go beyond regional narrowbody. Fielded widebody options is really just Airbus/Boeing duopoly, AVIC/Xi'an, UAC stumbling along from legacy USSR stack.
Their squircle fuselage works out really well. Really next-gen which makes sense because the Boeing and Airbus designs are decades old. I think they certainly have the chops to scale it up that bit to reach regular narrow body. But I imagine they just don't want to because that might mean trade sanctions from the US.
But I think the restrictions are more artificial/protectionist than actual knowledge. I'm sure sooner rather than later we'll have comacs flying in Europe. The Russian ones depend really on whether they resolve the war situation.
https://en.wikipedia.org/wiki/Comac
They have delivered 185 aircraft to domestic airlines. Maybe Africa is next?
Note that they so far use engines from western companies - GE and Safran. In fact, the vast majority of their primary suppliers are from outside of China: https://www.csis.org/blogs/trustee-china-hand/chinas-comac-a...
I guess it takes a bit of a war chest to get into this business simply because it isn't very easy.
There is a third, Embrarer. They have most of the market in small regional jets in some cases, but those are in reality very different than say a 777 or 787.
These two choices are conglomerates of what used to be a much larger set of manufacturers. In short Boeing, Airbus and it's suppliers are basically what is left of all the old big aerospace manufacturers.
These compete with the smaller versions of the Airbus A320 family (like the discontinued A318 "Baby Bus") or Boeing B737 family.
So, in that narrow-body and regional jet segment there are a few players.
But in the big wide-body (=2 aisles) long-range jets, there's only Airbus and Boeing.
For private jets there are Gulfstream, Bombardier, Textron, Dassault, and as you said Embraer. I think there was a recent new Entry, Honda from Japan.
Which is nothing compared to: 737 (447) 767 (30) 777 (35) 787 (88)
This. The entire market has been allowed to be monopolized through mergers and buy-outs. Russia used to have their own aerospace industry (and that fleet was reliable enough to be allowed to fly in Europe) but then Russia happened.
It's absolutely irrelevant what Russia did or could have done here in this industry.
Same with Chinese planes. If they ever manage to make a competitive passenger plane, it will not be allowed certification by US and European authorities purely for political reasons, the same way how their EVs are not allowed for sale in the US or how they aren't allowed to have ASML EUV machines. This isn't a fair game, never was.
The decisions on purchase of aerospace units is 90% (inter-)national politics and only 10% meritocracy, since both Boeing and Airbus are massive defense players making advanced killing machines, and no country wants to directly or indirectly fund the defense industry of their geopolitical rivals.
When a third country needs to chooses between Airbus or Boeing for their flag carrier fleet, they don't objectively compare the operational history and tech specs of Airbus vs Boeing and make the decision based on that, they just ask themselves "do I want to be in bed with EU-France or with Uncle Sam as my main ally and provider for the next 30+ years". Hence why most oil-rich middle eastern states chose Boeing as the US is their main defense provider anyway and don't want to anger them, especially when Donald Orange makes a visit to your state.
That's just how politics works when you operate at that level. Handshakes, dinners and bribes. Always has.