LCC’s have always created/stimulated additional demand that otherwise wouldn’t be there through low fares, particularly early on. Again, one of the reasons they do this is because the business model is predicated on volume. Stack them high and sell them cheap. (Even though not all the fares on any given flight will be classed as cheap)
Often the last lot of seats can bring in a great deal of revenue but you need a high load factor to be able to reach that point.