Yes, the POTUS has a lot of power. But he's abusing it in illegal ways, and trying to appoint people that won't stop him, and trying his best to ignore those who try to stop him.

Indeed. He is a bad President in a lot of ways. But a good deal of this stuff is a difference in degree, not necessarily in kind. With tariffs, Trump is far from the first President to try to find whatever possible claims of authority he could find in order to do something he wanted, but couldn't get through Congress. Obama most memorably had DAPA, Biden had his student loan forgiveness program - things they (charitably) had grave doubts were at all legal, but that they did anyway just because they didn't want to take "no" for an answer. Trump is far more shameless, and far less willing to generate the fig leaves of lengthy memoranda and legal studies of statutes than other Presidents - he doesn't care and doesn't want to wait.

Where Trump is a lot different is on immigration and criminal justice and military power. He's definitely far more of a hardliner on all these things. But for most of those things, the President really is in charge of those decisions - and those are legitimate choices within our system of government, and indeed any system of government. Choosing an iron-fisted strict-enforcement law and order policy certainly codes as "authoritarian," because it involves government use of force. The pictures are terrible. But those kinds of choices of how strictly/loosely to enforce criminal laws are permissible choices within non-authoritarian states. Not everything that is to the right of where liberals want to be on law and order, or the balance between security and liberties, is authoritarianism. It doesn't make those choices necessarily good or smart or just, but neither does it make them authoritarian.

And again, Trump is bad at Presidenting. Some of this is like Wile E. Coyote running off of the edge of the cliff but not falling for a few moments. Trump isn't immune to the constraints that hem in political power from overreach - it just takes a little time for those constraints to respond, and he just decided to run headlong as fast as he could without thinking of what the consequences would be. So now he finds himself in a place where he's had record numbers of nominees pulled, can't get his ballroom or even his war appropriations through Congress, can't move a massive bipartisan housing bill through a House of Representatives his party controls, etc....because he's been doing whatever he feels like doing for the first 15 months of his term. You can completely ignore what Congressbeings care about, trash their issues and stomp on their electability chances, for some time - but then you can't get their votes when you want them.

Nearly all Presidents pay attention to that at the beginning - they don't burn all their bridges and ignore cultivating relationships. Because they want the effective part of their Administration to last longer than a year. Trump chose not to, and that let him act a lot more freely/heedlessly for a while. But now, ordinary political reality is catching up to him. Which is one of the reasons you know we're not in an authoritarian regime - because there are consequences and limits to the Leader just going his own way.