[0]: https://www.hrw.org/news/2004/12/13/venezuela-chavez-allies-...
[0]: https://www.hrw.org/news/2004/12/13/venezuela-chavez-allies-...
I don't think there's a framework that can universally tell you whether supreme court expansion is always good in all cases or always bad in all cases. Taking effective action is bad when you do it for bad reasons and good when you do it for good ones. Unsatisfying but there it is.
Wouldn't the need for periodically choose replacements add politics instead?
John Adams and the Federalist Party reduced the Court from six to five; Jefferson restored the Court to six before expanding it to seven a few years later. Congress bumped it up from seven to nine in 1837, and Lincoln added a tenth during the Civil War. After the war, and at least partially motivated by vacancies that would have offered Andrew Johnson the opportunity to nominate justices who would screw with the Reconstruction plan, Congress reduced the Court from ten to seven. In 1869, Congress increased the Court's size to nine...and nominated two additional justices the very day the Court ruled paper currency--greenbacks--unconstitutional, who would then enable the Court to reverse that decision.
That said, there are non-partisan arguments for expanding the Court. We now have thirteen circuits; historically, each justice was responsible for a circuit but when appeals courts were added, the Supreme Court wasn't expanded. And then there's the expanded use of the shadow docket for more consequential questions. All of that's dramatically increased the Court's workload, and fixing it would probably be preferable...assuming that the act of fixing it didn't cause other issues.
Beyond that, not all of the expansion proposals amount to "add as many as we can." Many of them are tied to other reforms that are meant to lower the perceived stakes of each appointment, and grant a sort of regularity that ought to appeal to both parties without succumbing to what Venezuela current has to deal with.