Yup, we do. We prioritize things as they come in depending on how much coverage we have at the time, as to your point we have a lot to cover and they can't be in every spot at once!
Please be advised that the Community isn't the right avenue in posting jobs and receiving offers as we have the marketplace for this. To post your job, go to Jobs > Post a Job. We will ask you a series of questions to make sure you include all the important details that independent talent and agencies need.
You may check this article for more information on posting jobs in Upwork.