You don’t think the JF-17 has a shot? Congo is poor but it has lots of resources.
Poor has many aspects to it. Algeria, Morocco, and Egypt are poor, yet these are African countries that have the capacity to maintain large effective modern militaries including modern air forces. North African countries for all their problems are infinitely more competent and capable than sub-Saharan African countries. Even for sub-Saharan Africa, the Democratic Republic of Congo is poor and completely dysfunctional. A large portion of the wealth from extraction is either lost to internal corruption or given away to foreign mining companies.
More on the systemic dysfunction, the DRC is fighting a rebellion in the east against a militia equipped primarily with AK's and pick up trucks, and the DRC nearly lost a few years ago. Their only plan to fight the rebels recently was bribing the other competing groups of anti-government militias to fight for the DRC and to throw waves of poorly trained civilian militias with rusty AK's at the problem because the DRC's actual army is incapable of fighting a small regional rebellion by themselves. This plan has not worked, and now there is another group rebelling in the region. The DRC was reduced to begging their neighbors Angola, Burundi, and Kenya to send their troops to help fight the small rebel militia groups. That has not gone that well and Uganda and South Sudan will also now send troops. If you have been keeping count, it is now six allied sub-Saharan countries that have so far failed to stop small rebellions in the DRC.