The last time a POTUS wanted to change the number of justices it was proactive, a change to get something.
Yes, and ended up costing him considerable political capital and directly led to the demise of several New Deal propositions. FDR came out of that a clear loser. That is just a fact.
But more than a majority of voters are not happy with the shit McConnell pulled.
A Republican President and a Republican Senate majority that has held through two election cycles would indicate otherwise.
I just don't think it would be wise for Democrats to "go nuclear" again as doing so in the past hasn't worked out well.