Yes, 22% is not very much. But that is more than hyped Tribulus, Maca, Fenugreek, ZMA etc have done in non sponsored studies.
And royal jelly is one of the healthiest things one can eat, so this little t-boost is like bonus.
BTW, royal jelly supplements' daily doses contain even 20-80 times more active ingredients than the doses in this study.
I have combined things like royal jelly, ginger, garlic, ashwagandha, resveratrol and my test rose 60-70%. For an advanced trainee with good nutrition even that rose didn't produce very significant body composition or strength improvements, but otherwise I feel great.