Better for who? You're Canadian and I understand why you don't like him. NAFTA and all that. But from an American standpoint, USMCA is a better deal for us.
Every analysis I've ever read, except for yours, has stated that the so-called re-negotiation of NAFTA was an utter waste of time and money, nothing substantial was changed, except that Trump sent out a bunch of tweets that, apparently, some people believed.
A few weeks ago now, out of the blue, Trump threatened to raise aluminum tariffs on Canada, then a few days later called it off. Nothing happened in between that anyone could see. Were it me, I'd check the market trades of him and his buddies to see if they took advantage of any movements that happened. Similarly I'd check the trades that occurred the day after he dumped on Amazon. I think it's emerging quite clearly that he's simply an old-fashioned con man crook and that he's never been anything else. He can't understand the ins and outs of trade policy anymore that he can understand vaccines. One thing that is spectacularly clear is that he doesn't give a damn about the USA and especially its citizens.