Whilst acknowledging the default “don’t waste your money” view of buying something ready made, they are more convenient.
I’ve started having recovery-50/50 carb and protein shakes after long rides. You can get the same out of a meal but a shake takes 60 seconds to prepare and will stop you raiding the biscuit tin to get the hit you need.
Don’t think there’s much between the brands, you can have straight protein ( bodybuilder stuff), protein carb mix ( recovery ) and sometimes they mix stuff like creatine in there, dunno what that does.
I was sceptical but now I like em.