What an uncharitable take. First, as the paper says multiple times the actual function wasn't confirmed. Second, this is a methods paper designed to push the limits of how far back this technique (protein analysis on group 11 artifacts) can work and beats the previous limit by ~3000 years. It's not the most interesting paper in the world since their results are entirely in line with expectations and their methodology boils down to "collect samples and send it to MPI-GEA", but science isn't about publishing only the interesting stuff.