What do you think they are supposed to do?
It is a food substitute, i.e. nutrition, not crack!
I have ridden quite long strenuous routes without using any (gel, not crack) and on similar routes, I have used them. I noticed no difference whatsoever.
Porrage before a ride, take a banana or flapjack, cake half way round and a decent meal afterwards. Works for me.
You doubt they contain the ingredients that are listed on the packet?
I doubt they would sell them with misleading/incorrect ingredients.