Hey @designsfx
I was speaking in broad, general terms. Many of us aspire to purpose built rooms with perfect sound fields in them, but very few of us have them.
So, if you are forced to put your speakers in less than ideal locations and/or can't treat the room DSP / EQ in general may be the only way you can make things better.
Even with a purpose built room, we are usually limited in size and that has consequences as well. Having DSP /EQ in your toolbox is a really great thing. Besides the sub, another place where it becomes supremely useful is say with center channel speakers or speakers you have to place too close to a wall.