5th generation aircraft is a luxury toy, for J20, the single cost of J20, excluding profit、munition、 logisitic etc, is more than 120 million USD.
For 4th Generation aircraft, many fighers in the world. USA(F16\F15\F18),russia(mig 29 35\su 27 35), EU(typoon,rafael,gripen),china(j 10).
but for 5th Generation , now just USA(F22/F35),china(j20, initial production; FC31 prototype),russia(T50, prototype).
F22 is only for USA, did UK/germany/france prefer F22 or not, definitely.why not build 5th generation by themself? because it is not a easy job, just about dozens of billions USD