It should be separated out so the peasants can know just how much their government overlords are stealing from them.
If im buying something I just want to know how much I have to hand over. I dont want an intimate breakdown of how much of the cost is tax, how much is the retail outlets “cut” (a very proportion incidentally) how much is due to distribution (an even higher proportion) or whatever. I mean, if you buy something they don’t tell you how much import duty is on it.
For the record, many items do have the sales tax declared in the UK. Especially higher value items.