I think Donald Trump mostly wanted to escape legal responsibility for his actions and to exact retribution on those who acted against him. His ability to make his personal grievances sound like a bunch of other people's grievances seems to have made him successful. Every candidate runs against an incumbent on a platform of change, so every such candidate wants to "shake things up" to some extent. If you look at Project 2525 as the blueprint for Trump's second Presidency, then there is very much indeed a whole lot of shaking up planned.
I think there is some buyer's remorse. But we have to be careful not to generalize too much from the examples in the leopards-eating-faces thread. I've seen more commentary online by people who are saying things like, "Yay! Thank God it's finally happening!" This is mostly in response to allegations of waste, fraud, and abuse whose mitigation seems to be cover for enacting broad policy changes that may eventually end up causing second thoughts among Trump supporters, but presently don't seem to be. From my naive perspective, it will take watershed events such as a dramatic spike in death and illness, an outbreak of foodborne pathogens, a terrorist attack on a now-weaked military, or a systemic failure in some infrastructure such as air travel, the power grid, or the economy. It would take something big enough not to be written off as an incremental increase in the trickle of suck, and something fairly directly traceable to administration action.