For example consider the affordable healthcare act (aka Obamacare). A decade ago, the Supreme Court upheld it. This is one of their "healthcare is a legitimate area for Federal lawmaking".

But read their decision at https://www.supremecourt.gov/opinions/11pdf/11-393c3a2.pdf and that isn't what they decided. What they decided is that all of it fell under the power to regulate Commerce EXCEPT the individual mandate. However the individual mandate falls under the taxation power. None of this adds up to, "Congress can pass legislation because it is about healthcare." All of it is of the form, "The legislation passed fell under enumerated powers that Congress has."

Here is a sample passage from page 3 about why the individual mandate cannot be supported under the Commerce clause:

> The Framers knew the difference between doing something and doing nothing. They gave Congress the power to regulate commerce, not to compel it. Ignoring that distinction would undermine the principle that the Federal Government is a government of limited and enumerated powers.

Now suppose that Congress passed a law mandating universal access to abortion, while Texas has forbidden the same. By the reasoning that I just quoted, Congress' ability to regulate commerce does not extend to compelling Texas to allow commerce where none currently exists.

This does not mean that Congress is powerless. The next legal battleground is going to be over people leaving one state to get an abortion in another. Conservative states would like to ban it. As https://www.poynter.org/fact-checking/2022/can-states-punish... says, it is a tossup about whether such bans will succeed. But if there was specific federal legislation to allow crossing state lines for the purpose of abortion, that pretty squarely falls under the Commerce Clause. Because it is interstate commerce, in a commercial activity which actually exists.