I doubt it'll die completely
It's not as if Maplin are a Woolworths - where everything they sold could be bought elsewhere. Unless Clas Ohlson expand and extend their range, there's nothing on the high street which directly competes.
In retail parks DIY stores could be competitors.
I reckon Maplin could make money, but only by selling most of the stores. Limit to high footfall and student areas, and rationalise the stock.