The reported sex part of the relationship is rather vanilla and nothing scandalous. Trump was a sleaze to step on his new bride, but that's really a matter between the two of them and not really of any public interest.
Two non-sexual matters concerning Trump and Daniels, however, are critically important. First, the elaborate coverup to hide the affair from public scrutiny is already of interest to Special Counsel Robert Mueller, who is conducting the criminal investigation into the President and his associates.
The bottom line: the coverup could be viewed as a criminal conspiracy and open Trump to prosecution.
The second important takeaway are the threats that were allegedly made against Daniels. While such matters in most failed relationships are often a matter of he-said-she-said, this situation is different because her lawyer has alleged that they have evidentiary proof.
Trump also has a history of being in the penumbra of threats made against his adversaries. People have complained to law enforcement authorities in the recent past about physical threats made against them after they parted ways with the President (details here and here).
We should know by the end of this week if this latest scandal has any legs. It's curious how Trump so consistently has kept his silence, refusing to answer any media questions about the veracity of Ms. Daniels' claims.
The rare times Trump remains silent in public are often the times when he's speaking the loudest of all.