Can my indoor cat live off just dry food?



We have an indoor, deaf cat who currently eats tinned cat food and cat biscuits. However, Ive heard a lot of bad things recently about cheap, tinned cat food - apparently it isnt good for cats / gives them a short life expectancy / has a form of kitty crack in! (Whiskers apparently!) Weve been recommended to feed him some good quality dry food such as Science Plan. However, is it ok to just feed a cat dry biscuits? Does he need the wet, tinned food for nutrition or not really?