If your thesis is something that is generally agreed upon or accepted as fact then there is no reason to try to persuade people.Example of a non-debatable thesis statement: implies that something is bad or negative in some way.
Some people might think that this is how we should spend the nation's money.
Furthermore, all studies agree that pollution is a problem; they simply disagree on the impact it will have or the scope of the problem.
No one could reasonably argue that pollution is unambiguously good.
The broader your claim is, the more evidence you will need to convince readers that your position is right.
Example of a thesis that is too broad: There are several reasons this statement is too broad to argue. Is the author talking about illegal drug use, recreational drug use (which might include alcohol and cigarettes), or all uses of medication in general? Is drug use causing deaths (and is the author equating deaths from overdoses and deaths from drug related violence)?