The Supreme Court 'Shadow Docket' (2022)

A lifetime appointment now tends to lock in the political ideology of the justice at the time they were appointed, for decades. A limited term would result in more fresh perspectives over time and greater ability to reverse the decisions made that were not in fact based solely on "interpretation of the law".

Using the "bad apple spoils the barrel" analogy, having a routine schedule for refreshing the apples will eliminate the bad apple more reliably than only refreshing the barrel on a random and unpredictable schedule.

It also helps voters take into account with more certainty the views of Congresspeople and presidents regarding SCOTUS when they vote, as now they have no idea when either of those two branches will have the opportunity to appoint a replacement justice.