Well it's not just "Cohens word" is it Simon?
We also have audio recordings of the two men talking about it. There are e-mails, text messages, shell companies, and wire transfers that all back up what he's saying.
Had Trump paid the money out of pocket AND reported it - than there be very little legal exposure. But that's NOT what happened. Instead, Trump instructed Cohen to set up shell companies and pay for it using a personal bank loan. Then, after the election, Trump turned around and reimbursed Cohen triple his money using a retainer BILLED TO THE CAMPAIGN.
Take off your MAGA hat for a second and address what ACTUALLY happened. It's not "just Cohens word". There's a mountain of evidence behind what this guys saying.