While that is exactly what the U.S. Constitution, Article III and Article I say - Article I giving exclusive authority to legislate (create and amend federal laws) only to the U.S. Congress, Article III not giving similar authority to federal courts, including to the U.S. Supreme Court - the U.S. Supreme Court justices usually never follow what they were sworn and are paid to do.
First, the choice of cases.
You may not be aware that the "discretionary right" of the U.S. Supreme Court to take only cases they deem "worthy" for their pre-eminent review did not always exist.
It was given to the U.S. Supreme Court by the U.S. Congress only in 1925, on the request of the U.S. Supreme Court complaining that they have too many cases to review - too hard a job to do.
Instead of expanding the court to be able to handle all cases that come their way, or impeach justices who, in response to a growing caseload, asked to allow them NOT to give people an opportunity to be heard, the U.S. Congress condoned the justices claim for their right to be lazy and gave them the right for "discretionary" picking and choosing which cases they want or not want to hear on a final appeal.
And do they pick since then.
Imagine a completely discretionary job.
On the one hand, all SCOTUS judges are sworn to uphold the U.S. Constitution - which, by the way, does not include in it Supremacy Clause precedents of that same SCOTUS.
On the other hand, by the Supreme Court Act of 1925, SCOTUS judges are at liberty not to do their job - not to take any required number of cases per year.
The 9 of them occupy a huge marble palace, are paid royal upkeep and are given a royal crowd of servants, but are not required to do a damned thing. Literally.
All of their job is discretionary.
They can pick to hear one case per year if they want to - or not to find any one case worthy of their review in any given year at all.
They routinely toss meritorious cases, citing multiple violations of the U.S. Constitution by civil rights plaintiffs, and especially by pro se plaintiffs.
Yet, they routinely take cases of corporations - and I wonder how many of those fund their wining and dining, their and their families' trips, "scholarships", speaking engagements and careers.
So, let's look at the very "principled" decision of Justice Gorsuch.
The case the "discretionary court" has picked is of an auto debt collector.
You must agree that the non-payment of loans to people who lend money for consumers to buy cars is the most important constitutional problem in this country to tackle.
So, out of 8000 of petitions, most of which (99%) are not given any review, this one was picked, reviewed and decided, in favor of the debt collectors.
And in this case, Justice Gorsuch, getting in the high horse of the "rule of law", has stated that, once again,
- it is not for the Court to amend statutory law enacted by the U.S. Congress, and
- if the U.S. Congress wanted to include or exempt certain entities from the reach of a statute, it would have done it.