the legality of his actions was much more easily provable as a crime

Trump was convicted of a full 37 counts in the Stormy Daniels indictment. He's lost multiple civil cases for defamation, totaling hundred of millions in judgements. Rudy Guliani lost his law license in New York over electoral interference. And 623 of the J6ers have received sentences. The idea that these folks are difficult to prosecute is absurd. But you do need to get them in front of a jury first.

Trump’s case involves not only a lot more possible statutes he could have violated, but also a lot of arbitrary actions that don’t perfectly fall into a rigid box of “this is legal” or “this is illegal.”

You can wave your hands at the legal system and insist "Its too hard!", as so many in the Democratic Party have already done. But in the few cases where Trump or his minions do actually get in front of a jury, they consistently lose.

Plus, if you have more money to draw out legal fights

OJ's original criminal legal team bankrupted him. Once he was out of cash, he started losing courtroom fights. He eventually ended up in jail for assaulting a Vegas pawn shop owner over some illegally fenced sports memorabilia.

Trump's been involved in substantially more criminal activity and could be prosecuted significantly more than The Juice. But cases have to go to trial first. We have 91 indictments, but only one case that's made it through a full trial, in large part because federal prosecutors are dragging their heels.