In other words, it depends on the type of gambling, with gambling like poker or sports betting then what you said is true and the other side with slot gambling then luck is an absolute necessity that plays a big role in making players win because in this one gambling there is no accurate strategy or skill to be able to win other than luck on your side.
I myself assume that all types of gambling require luck as well as games that require strategy or skill to do it, it's just that there is a slight difference here, where some do depend purely on luck and some can increase their chances of winning with a good strategy or skill that we have.