Phones4U used to be awful and their marketing seemed to be aimed at the more erm... chav infested end of the market, but they did get better and I bought my Moto E backup phone from them online without any trouble.
Although you can argue that these phone shops such as Phones4U and CPW are just middle men, they did provide one important thing - Unlocked phones on the High Street.
Not everyone has the money for an iPhone from an Apple shop or a Nexus from Google, so giving people the ability to select their own phone and own network is an important thing, and it is a shame that one more shop has gone that provided that. I hope that they do find a buyer and get bought out from administration.
Saying that, the size of some of their shops are ridiculously huge! I have no idea why a shop selling mobile phones has to be the size of a car showroom...