Ordering Pillows for a Couch

We might get a couple of extra pillows for the couch we've ordered.
The sample upholstery fabrics we took home from the furniture store to check out seem variously stiffer and/or scratchier to me than the material on the various pillows we already have lying around here.

Which prompts me to ask the following questions:

Is there any reason why the pillows need to (or should be) be made from the same materials that couches and chairs are upholstered with? Couldn't one use more "run of the mill" fabrics, not designed to withstand 20,000 double rubs, or whatever? Granted the pillows will get some contact, but we're not actually literally sitting on them, routinely.

Assuming it is not necessary to focus on durability to the same extent, is there any particular reason/advantage to buy pillows at a furniture store? As opposed to going to the local fabric shop, and getting a local lady to recover our pillows, or other pillows they might have, with whatever fabric we like there, which may well not be suitable for a couch or chair (but might be softer to the touch, as is the case with our existing pillows) ?

Sure! Mix up your pillows, that's the fun part....at my house for example, I have pillows of suede on one side, fabric on the other atop our leather sofa. The suede is very nice to put your head on. No real advantage to getting pillows from the furniture store other then down interior fill and a huge choice of covers. My wife goes to Pottery Barn for $ 30 pillows, but I can't stand them because the fabric is cheap n' scratchy. I like my suede....