Speed-wise, he's the slowest out of the big four. Strength-wise, everybody is catching up. Hocker just shocked the world with an indoor 7:23 in his only serious attempt. He could definitely get to around 7:20 outdoors, and Kerr and Nuguse may be even faster, so Jakob's only edge over his competitors is going out of window. Not to mention Kessler and Laros getting better and better.
I don't see how he would win another world title tbf.