Quiz party is a 15 category game and as you know you choose 1 of 3 categories as Aminiel has already said. There would not be enough questions for just a sports game at the moment plus the sports would require their own category and Quiz party doesn't support that. People would want the same for other categories making it a very difficult task to do.
Questions have been validated but validation is only one part of Quiz Party. "new Questions" most of the questions we receive are not "new questions" in the true meaning of new and that's why we have so many repeats. When validating questions you have to check every question and they should meet our existing standards.
Validating starts with you and you have been able to do that since the launch of Quiz party. You can do that by checking questions you get when playing Quiz party or Duck racing. If you find errors you can press control G to flag up the question in Quiz party. Unfortunately, you are not able to do this for Duck racing, However, you can send the question to YNWA's in-box and those questions will be checked out.
The other way you do your own validating is when you send in Quiz party questions. You can check your spelling and even Google your own question to see what it makes of it. Fortunately now there are other websites or even quizzes on Youtube that have good questions so that is another way to find good questions if you are not so good at writing good questions in English. You can also see the questions we have validated and send in questions in the style you see in the games. The more errors there are in your question the more likely that not all of the errors will be found when validated. Imagine looking through 15 pages of 100 questions for just one category trying to find errors.
I have been going through every question looking for repeats/errors/poor choices as answers. I have gone through Literature, Music and now near the end of Cinema. So far I have found around about 75 repeats although a couple are in other categories. 90 to 95% are very good but even 5% of 18,600 or maybe the percentage is a bit less but still a lot of questions to improve upon. I would say from the evidence I have seen that Quiz party validators have done a very good job but have at times validated questions that were too difficult to validate, not wanting to let people down meaning even with their best efforts there were some bad errors left in some of the earlier questions we received. Maybe this lead to the odd question where a mistake has been made where I know 100% they would not normally make that error.
With losing Merlin last year and thinking about Corona it has made me think about Quiz party. I could have validated more questions and the numbers would be a lot less and I could have added more questions myself but I want to ensure whoever comes in after me has a very good database of questions and not left with a black whole where a lot of the earlier questions still need improving. Quiz party has been going for over 4 years and even in another 40 years time few of those questions would have not been flagged up. People have more than enough questions to be going on with so if some people have to wait a little longer for their questions to be validated then so be it. I see little point asking someone else to validate questions if It means I will have to look again at all the questions later to find they have made simlar errors to the ones we had at the beginning of Quiz party.