China spent tens of billions of dollars, and decades developing this engine technology and it seems they may have crossed that line of success with the WS-15 engine. Türkiye is going through that same learning process now for the KAAN engine, they have spent decades building the core infrastructure, people and institutions to get to that point. Japan has engine manufacturers, but they have not managed to cross the line of developing fast jet engines, when they do, they will pay the price in coin to develop that technology. Same goes for Korea who are now looking to start their own fast jet engine development project for the KF-21. France has an aerospace manufacturer of engines, but even with all that France has, it lags behind the UK in this field.
Fast jet military engines are hard to develop, really hard.
All this is because this technology costs serious serious money to develop and alot of time and you need deep institutions and a good quality university network to help.
Yet, India expects this countries to give over their hard earned technology for pennies on the dollar and they wonder why they don't get anywhere.