The problem here is, you're oversimplifying the process of building a jet engine capable of powering Kaan, and then on top of that, there is the complicated process of making sure that engine is actually a 5th generation engine with required characteristics.
I know people here scoff at the comparison but it took Chinese almost 20 years to get WS-15 ready to fly with JS-20. All the knowledge we claim to have through building F-16s and other engine types, they also have that and more since they've also been building WS-10 for almost 10 years now. They had access to Russian tech AND Western tech through their espionage and it still took them a long time to get here.
We can be proud of our engineers for what they achieved so far, and I am, and trust them for what they can do, and I do, but we should still be realistic. Even US abandoned new engine for F-35 because it was such a costly and time consuming undertaking. Our people, and most certainly our leaders, have a tendency to sugarcoat things and present the best and sometimes unrealistic scenarios to boast. I'd rather we have the cold hard truth and get pleasantly surprised afterwards, rather than get caught with our pants down.