Some legal precedent regarding presidential powers is likely to come out of this case, whenever the decision is released.
That could be why justices were asking questions about issues unrelated to Trump’s specific situation. They know the results of this case could well be cited as a precedent years from now in some other case.
“Some legal precedent regarding presidential powers is likely to come out of this case”
Scotus has already upheld qualified immunity for other government officials, not sure how they could justify the president liable while judging lower level scumbags exonerated.