Even with View > Wireframe View, I find a map is harder to read in JOSM than it is through iD, which is one of the reasons why I much prefer working with iD… but JOSM is sometimes required, such as mass-editing ways.
For instance, it’s hard to see if a way is select through SHIFT, and where it ends :
Or use filters to filter out elements. With filters you see only the ways/nodes/relations that you are interested, and besides that, it speeds up josm (at least rendering) when working with a lot of elements.