Europe is developing 6th Gen fighter(s) already though. And yes, Europe produces a 5th Gen fighter. The f35 is made only in USA and Italy, although I share the worries on having a potentially brickable device

5th gen is a nonsense marketing term. It is far less about the plane itself and more about how it integrates into a force. This is why russian figthers are pretty useless: they are not integrated with the rest of the force and they lack coordination. The russians do not even have the ability to discriminate between their own planes and enemy planes when making decisions to launch AA missiles.