They won't go under either as they are now one of the few national chains that offer try before buy on products. You can't do that in argos, that sells a lot of the same products, nor get advice on them etc. When someones washing machine breaks and they need a new one, they often won't try order online, instead they'll get in the car and try and pick one up the same day, especially if they have a family.
Yeah, I didn't think Currys PC World is due to go under, especially after announcing that they faired Xmas quite well.
I believe you are wrong on Argos though.
Yes you can't really get advice or look at the items properly (though I believe you can ask) but they have always carried their 30 day return policy for as long as I can remember.
Ever since I was a child I remember there being a queue for customer service of people returning things. Its also the reason you will occasionally buy something and its obvious it may have been opened before. So Argos has always had one of the best returns policies on the high street.