Maybe you're using a fuzzier definition of "law", but there was never any federal legislation that guaranteed access to abortion. That is what we need.
"In law, common law, also known as judicial precedent, judge-made law, or case law, is the body of law created by judges and similar quasi-judicial tribunals by virtue of being stated in written opinions.[2][3][4] The defining characteristic of “common law” is that it arises as precedent. In cases where the parties disagree on what the law is, a common law court looks to past precedential decisions of relevant courts, and synthesizes the principles of those past cases as applicable to the current facts."
Though it does kind of make sense, after all it's the United States of America, not the United People's of America, or the United Local Jurisdictions of America.
The States can have rights that supersedes the people apparently.
My reading of the particular passage[0] in the Wikipedia article is that while Federal courts are no longer independent sources of common law, they operate along with other systems that are, and often impact the common law of the several states with rulings that set the limits of Federal, State and individual power.
As such, the reality is a bit more complicated,
N.B.: IANAL and this is not legal advice.
[0] https://en.wikipedia.org/wiki/Common_law#United_States_feder...
But it does. Our common law system treats judicial rulings as law. There is nothing stopping the supreme court from ruling on literally anything they like. They could make cars illegal in the next session if they wanted.