In some parts of the world, euphemistically named “night soil” is used as fertilizer.
Doing much of anything else with waste is kind of stupid.
That is, after all, the natural cycle. Animals, directly or indirectly, feed on plants. Then the animal waste goes to fertilize the plants.
Instead of putting waste back onto the land, where it is beneficial, we have historically dumped it in rivers, where it is most definitely detrimental.
There are, however, difficult problems with using city sewage for fertilizer, mostly having to do with presence of chemicals and heavy metals. Handling the pathogen load and odor we normally think of as the problem is trivial by comparison.