They've actually done so numerous times already and have several cases on the docket that look to be leaning against him as well. There's a reason why most serious pundits saw this ruling coming a mile away, because SCOTUS has proven to not be a puppet of the administration.
Several justices are openly taking bribes
https://www.propublica.org/article/clarence-thomas-scotus-un...
https://www.propublica.org/article/clarence-thomas-harlan-cr...
and still this current ruling was a 6-3 vote.
You can still technically bring charges against the president for things they do while in office.
Practically speaking, after that ruling, you cannot, short of hypothetical scenarios so incredibly unlikely and egregious that even the incredibly unlikely and egregious acts of this administration don't meet that bar.
The president doing horribly fascist things with ICE like obliterating habeas corpus? Using the military to murder people in the ocean without trial? That's fine.
Screwing with the money? Not okay.
See also how the prez is allowed to screw with any congressional appointees except the federal reserve.
Actually they’re still doing it. I saw it not 2 minutes after seeing this post initially. The justifications for why they were “good, actually” has gotten increasingly vague though.