That is not correct. Abortion was legal in New York prior to Roe, for example.
But beyond that, we have to look at what can be achieved when and how. To create a federal amendment outlawing abortion would take 2/3rds of the Senate and 3/4s of the state legislatures - and please show us how that threshhold can be reached anytime soon. But if Roe is overturned, many states would quickly outlaw abortion within their borders.
Is that perfect? No. But is is doable, and would save at least half of the children aborted nowadway while public opinion shifts to the level of a consensus that can cross the amendment threshhold.
Don't make the perfect the enemy of the good - a lot of lives can be saved with the federalist argument sooner than by waiting for the perfect solution later, and the federalist approach can be the means to reach something better later.
And in NY are you talking about the law passed in 1970?