No. Decentralization is the transition from a bigger part to smaller parts. California doesn't get to dictate Texas.
If your issue is with government having overarching reach, I'd agree that it doesn't matter if it is state or federal (national). But if you believe that you have freedom because the federal government gave it to you, then that's not really freedom.
You seem to not understand the core of leftism.
So let'a get through that.
A leftists is going to look at PRACTICAL effects. What is or has happened. Not what is on theory.
If biden decided to reduce student loan debt by 2,000 for each person. We would say "that's not meaningful change" and that's because it
A. Does not address the core issue aka the for profit education system
B. Does not account for the persons living standards. It would cut debt down now, but if they're in a dead end job because the market is shit, they're going to get right back there as interest over time occurs.
So therefore it's not meaningful change.
So let's look at roe v wade, specifically the removal.
What does removing roe v wade effectively allow?
It allow's states (European version) to regulate a person's body.
Sure they didn't say outright abortions are banned.
BUT THAT'S THE ONLY GAINNED RESULT
That's the ONLY change, practical result that occurs with it's ability to be removed or applied. That the state government can now regulate people's bodies.
This is not a decentralizing. This is centralizing power and trying to hide it with a paint job.