and why were most of the cases thrown out?
Two things:
1. You don't need -- and often don't have -- proof of allegations to go to trial. A vital part of trials is discovery, where you get data and depositions by court order. You can't get that beforehand.
2. A court rejection of a case says nothing about whether the allegations are true or false. Because there was no discovery. And no trial.
For your question, I'm not going to spend 100 hours to find every case and dig it out of a court system. But for ones mentioned in the news, the two most-common reasons seem to be lack of standing and insufficient evidence.
---- Lack of Standing ----
Lack of standing means, even if you have lots of evidence and were wronged, the court says it doesn't have jurisdiction. Often that is appropriate. But there can be situations where you did get screwed over, and a circle of courts passes the buck.
Like the automated-help loop: "Press 1 to get help with your platypus. Press 2 for help with your phone account." You press 2. "Press 1 if you need help with food for your platypus. Press 2 for other items." You press 2. "Press 1 if you need help with toys for your platypus. Press 2 to go back to the main menu."
---- Insufficient Evidence ----
Here, a judge deems your evidence too weak to start the process of trial, discovery, etc. This is a way to reduce frivolous law suits. Often, judges err on the side of allowing suits. Like the McDonald's hot-coffee case, Lindsay Lohan's case against E*Trade over a talking baby in an ad, and so on.
In the Trump cases, the courts went for a high bar. OK, but then you can get a Catch 22 situation. You can't get stronger evidence without discovery. You can't get discovery without stronger data.
Both lack of standing and insufficient evidence are often noncontroversial. But they are also tools you can use to stonewall someone. Things like sloppy paperwork or time limits are much less subject to personal opinion and don't much lead to controversy.
