I'd also add that Elves and Dwarfs are conservative. They do not accept changes in their society. Humans adept and outlive them as a species on the long run.You nailed it in this sentence.Religion and organization is what allows humans to achieve deeds which no elf nor dwarf would consider conceiveable.Humans tend to be versatile all-rounders, and sometimes their fervent religiosity or penchant for organization marks them out from the rest.
Elves may be smarter, nimbler, etc, if they don't accept to live in large cities and share their science in universities, they cannot compete collectively in the long run.
Dwarves may be tougher, if they lack theological speculation, they won't try what requires faith.
But here Vermin come, ratman are taking almost all the advantages of humans over elves/dwarfs and make it better.