This is because once upon a time there was only one pizza world championship: that of Salsomaggiore which today is held in Parma, but today in the same year I think there are at least 3/4 championships that claim to be "world championship".
Therefore, in the same year there are 3/4 world champions of pizza in charge, for this reason it would be better for each winner to specify "I am the world champion of that particular championship" and not just say "I am the world champion and that's it" leaving understand to those who are not in the sector that he is the only pizza world champion.
But let's also see how voting is done in most of the world championships.
In those that I have personally seen, the jury made up of professionals in the sector vote not only for the pizza but also for the pizza chef, let me explain: the pizza chef brings a pizza to the competition and personally presents it to the jury, after having also introduced himself. The jury then evaluates the pizza but without saying it also judges the person in front of it, so the judgment cannot be impartial. If there are friends or acquaintances of that pizza maker on the jury, I don't think that the judgment on his pizza will be given truly impartially, not to mention if that pizza maker is not particularly nice to someone on the jury or if he had an argument before. Then we also remember that each championship is organized by one or more schools for pizza makers so if the jury which is largely made up of pizza makers from that school is faced with an excellent pizza made by a master from another school it will be very difficult to favor it compared to that made by a pizza maker belonging to the school to which he belongs.
Lastly, there are a couple of these world championships that are organized together with a mill and strangely, every year someone who uses the same flour as that mill always wins.
For example, I have personally seen in some of these championships organized together with a Mill, delegations of Japanese who already in their country used the same brand of flour that had organized the championship, participate in groups of 20 people and strangely one of them placed second or third. It seemed to me a sort of thanksgiving for coming from so far to participate and for using that flour in their country... but this is just my opinion.
A few years ago already in 2006 in our championships, those of Pizzaitalianacademy (which have never claimed to be called world championship) I started using a voting method which in my opinion is the most impartial: that of having the pizza of each competitor without the jury knowing who made it and after voting for it, show the jury the pizza chef who made that pizza. In my opinion, this is the only way to ensure true impartiality in a pizza championship where only pizza is to be placed first. Over the years since we started using this voting method in our championships it has often happened that pizza makers with less years of experience have won compared to the more experienced ones but at least the pizza won and not the pizza maker.
Put yourself in the shoes of a jury, if a 55/60 year old pizza chef comes along and maybe a well-known name who made a bad pizza that day because he had a high fever that day (just to give an example) in your opinion Would the jury ever give him a low grade that he deserves that pizza or out of respect for the person would they treat him better than a 20-year-old boy who made a better pizza than his that day? I say the jury would give a higher grade to the older pizza maker even if his pizza that day was worse than the boy's. In this way it makes no sense for a good boy to go to a competition where there are older pizza chefs and perhaps well-known pizzerias because he would always be penalised.
On the contrary, according to you, in a competition where the voting system that we have been using since 2006 is adopted, i.e. to vote for the pizza without seeing who made it and after the vote to present the pizza chef, pizza chefs who have a certain name would present themselves to compete ? I mean those considered by certain rankings (which I consider a farce) the best pizza makers in Italy? The answer is no! Because they are not sure of winning, they know very well that theirs is by no means the best pizza in Italy as it is often praised in the newspapers and they would be ashamed to see themselves surpassed in the standings by talented young pizza makers or by unknown pizza makers compared to them . If they were so sure that their pizza would be the best pizza in Italy they would present it without showing their face next to the pizza convinced of the winning result instead they abstain because they have their victory when "that certain paid journalist" goes to write that theirs is one of the best restaurants in Italy or in the world. Here we go back to the argument that I addressed in another article that "there is no best pizza chef in Italy and in the world" everything is subjective to the personal judgment of the judge and universal judgments valid for everyone cannot be given.
This is why certain pizzerias make me laugh who boast of writing with large banners at the entrance visible to all "World champion year ...." or "third place in the world championship year ..." etc .. They are all titles that leave the time they find ... it's just marketing! I'm not saying it's wrong to do it from an advertising point of view because customers are attracted even that way.
I am not against the "pizza championships" I organize them too but I always say before starting that what is about to happen is a party, a day of meeting and discussion and that the best man for that day and for the judgment wins of that jury but that no one feels defeated because it's just a game.