Yes, as I mentioned most fields (as far as I know) do not have a separate section for the conclusions, and in a mathematical paper (with proper layout and proper section numbering/naming) such a section would indeed not be all that useful. But in the experimental and theoretical physics papers, as well as the biology papers and some papers in medicine, the Results section is full of (raw) experimental data and/or calculations, and the Discussions section contains several pages about possible improvements to the presented model/setup and sometimes the strengths of the used method over previous attempts. The important conclusions are hidden somewhere amongst this multi-page defense of the authors' approach to the problem, which isn't optimal. My teacher used to say: "If your audience didn't remember your main point, then your presentation has failed.". In most experimental fields a short summary of the most remarkable conclusions would be helpful to remind readers of the implications of your research, and often I have found this section to be missing (not just absent but also desired).

But I stress that this is just my personal experience, and even if changing the layout improves readability it might be better (career-wise) to stick to the conventions of your field.