The court rejected Trump legal team accusations because the election authorities are held in the hands of local legislators in each state! That means only local legislators can collect the evidences and present them to court! Or, they decided to accept or reject the election results by constitution!
But, most local legislators rejected any investigation and audit for some reasons! Without physical evidences are presented by local legislators, the court can not do anything! It is the business of legislators and it is not the business of courts! As a result, It becomes a deadlock! (Courts rejected for hearing but it doesn’t mean it is a fair election! )