is this real, do dog biscuit actually taste sweet???
Depends on the brand and kind of treat. When my last dog started having dental issues I stopped buying most pre-made dog treats because almost all of them have way too much sugar. Dogs adore sweets, so an easy way to make a treat appealing to dogs is to add tons of sugar. In fact, most of those soft chewy treats are basically glorified meat flavored twizzlers.
I was shocked after I started reading the ingredients on pet food and treats before buying them instead of naively trusting that they wouldn't sell food for pets that was actively bad for them, a lot of pet treats are pure garbage. You can even find "dog cookies" at places like petsmart that look exactly like human cookies... because they are. They're literally the exact same type of vanilla sandwich cookies, just packaged differently. They're probably made in the same factory.
Frustratingly, even most soft treats for cats tend to have sugar in them (I think because it helps them retain their moist chewy texture), and cats can't even taste sweet, so it's wasted on them.