Isn't the main reason abortions can take place that the supreme court rendered a decision in Roe V. Wade? That might not be the same as making an actual law, but it surely establishes what is and isn't possible under the law. Why can't the supreme court reverse the decision effectively rendering various anti-abortion laws that were rendered null and void viable once more?Yes, as a justification for changing the law. Changing the law isn't the Supreme Court's job, their job is interpretation. Abortion will be bannable in the US if and when the legislature makes it explicitly so, that's why personhood amendments have been drafted, so as to make the constitutional stance clear. If that doesn't happen, the court's not going to divert from precedent very far.
To be clear, if Barrett was a legislator, I guarantee she'd be fighting to ban abortion, because legislators do craft law based on their personal stances. She isn't, she's a judge, she has an obligation to the law as it exists.
The supreme court is far closer to a legislative body than a judicial one.