Not at all.

This is a known hazard when working on waste-water networks. There are a few deaths every decade, despite nearly everyone having gas detectors (and being told to use them before going into a manhole).

At high enough concentrations, H2S just shuts down your smell receptors.

People who die in such situations don’t not smell the hydrogen sulfide. They just either have no way out quickly or they keep going in spite of the danger. I’ve been in such situations.