Lack of standing.

Trump only actually had half a dozen cases of his own. Other citizen groups and voting groups drafted the other cases.

Since those groups weren't the ones disenfranchised, they were thrown out before evidence was even looked at. There was no court case at all, not only did HE not lose them, they weren't even lost. All can appeal to a higher court, but there wasn't enough time/money from independent groups to do so. Most court cases can take several years.

The cases Trump actually had, they used the oldest trick in the lame-judge rule book:

"If the damage is already done, say they should have filed the case BEFORE damages. If the election hasn't happened yet, there haven't been any damages incurred, so they can't file a suit. In other words, GFYS"

Trump has not lost a single case, as no ruling has been delivered. They all have been tossed aside before any evidence was heard by a judge. They then go to a panel of judges on appeal who also toss the case. Then it goes to the SCOTUS and then they can just say there is no standing and while you still have not lost, and the rigged system successfully ran the clock out.

This trick has been used so much that Trump knew the courts would never go anywhere. The court cases were all just to show how rigged the court system has been against the American people for a long, long time.