I make no judgement on skill...my definition is purely results focused, which is exactly what I believe was asked by the OP.
Maybe the OP can clarify whether they meant the most skillful player of the decade, or the player that has had more success (that is still subjective, but clearly different to skill level).
By your logic SVB should be one of the greatest Mosconi Cup players of all time because of his skill level, despite a very poor (team) win record and therefore a lack of success.
You didn't read very carefully. The definition I gave, which is the correct definition, was the "player of the decade is defined as the person that has demonstrated the greatest level of skill over a specified time frame, in this case the beginning of 2010 to the end of 2019." Not just who we think has the most skill in our opinion, but who has done the most to demonstrate it over the decade and demonstrated means results--ALL results, and with those results weighted SOLELY by the quality and depth of the field.
The problem with your logic (among many) is that you only want to consider world championships, which answers the question of "who has the most world championships", but that quite simply isn't the question that is being asked. The question that is being asked is who is the player of the decade. Who has the most world titles will very often have a different answer since it is a totally different question. You have to stick to answering the question being asked of you, not some other random question even if you deem other said random question to be a more important one (and whether that is true or not is another unrelated debate entirely).
Another problem with your logic aside from not really wanting to consider anything outside of world championships, is that to whatever minuscule extent you are willing to consider the US Open and any other events that don't have the word "world" in the title you are not giving them nearly enough weight either because of the location in the world in which they were played, or because they lack the word "world" in the title. First, location and the word in the title should be given zero consideration. None. Zilch. What matters is how strong the field was in each event, and how deep it was. If a world championship has a lessor quality or less deep field than say the US Open then it should carry less weight, and if it had an equal field to the US Open it should carry equal weight, and if it had a very very slightly better quality and depth of field then it should carry very very slightly more weight. The name of the event or where it was played is immaterial.
Your analysis needs to be honest, not biased, and up until now it hasn't been honest at all and you have been letting your bias do some bad analysis.