Jet fighters are not cars. A lot of big car selling no nos are industry standard for jet fighters.
Pretty much everything for sale are put up on sale long before the 'finished' version is fielded.
Typhoon, Rafale, every Flanker export variant ever, PAKFA, F35. List goes on and on.
Problem is that Chinese fighters are designed and built for winning wars, not necessarily every battle.
Chinese fighters up until the latest J10, J11 and J20s were designed like WWII T34s, not the best, but good enough yet cheap enough to be bought and built in vast numbers of needed.
Western fighters are built like WWII tigers. Best of most things, but stupidly expensive.
Chinese fighters are good for war between peers, western fighters are good for peace and beating on hopelessly outmatch foes.
Most countries, when they shop for fighters, are not actually expecting to need to use them in combat. So top specs seem more important than wartime sustainability.
The situation with weapons are worse. Most that buy western fighters only get a modest weapons package because of the high cost. Needless to say, that could massively bite them in the backside in the event they actually need those fighters and weapons. Just look back to the Falklands and Argentina with their Exocists.
The JF17 is also massively disadvantaged by the institutional racism of the 'international' (read western and Russian) military aviation 'professional' community, who generally are in the pocket of western and Russian arms manufacturers, and goes out of they way to put down the competition from China.
China's peaceful diplomacy means there is nothing to offer an alternative viewpoint.
Sadly, what Chinese weapons need is a war where the latest Chinese weapons are used properly. If China or Pakistan goes to war and shows the world what Chinese weapons can do in the right hands, I'm sure countries would be lining up. Only China would never start or get involved in a war just to aid arms sales.
On balance, between selling loads of weapons and not going to war, the latter is preferable.