When to use Subdivide Collapse?

I use Subdivide Collapse almost all the time, I switch to Subdivide Edges, when Subdivide Collapse doesn't give the result I need, for instance when making sharp creases...

Now, personally, I don't think I ever used Collapse Edges, but I'm sure there is a use for that as well  (I tend to increase the Detail Size and then use the Simplify Brush, with Subdivide Collapse, instead of just Collapse Edges...)

I can think of Subdivide Collapse as an eraser almost. I've been sculpting something and I'm not too happy with it, I can always wipe out the shapes by a subdivide collapse stroke. It collapses geometry depending on your pixel size, it doesn't preserve it like relative detail does.

All good, valid advice here 👍

Generally I see use subdivide collapse for the first ~50% of a sculpting workflow. This is the most flexible period where I try to keep things freeform. Since subdivide collapse regenerates topology with each stroke, it prevents me from committing to any details. Just broader shapes.

For the latter ~50% of the sculpting workflow, I switch to subdivide edges which only regenerates topology if the existing topology is below the detail size threshold. This means I can commit to details and refine existing shapes.

I also will commonly use Subdivide collapse as an erasing moment as Omar says.