The U.S. Constitution puts in place a structure of “checks and balances” between the three branches of government to prevent tyranny, and it is that concept that limits the degree of oversight of SCOTUS by Congress. However, this structure also enables tyranny when the same wealthy parties buy SCOTUS justices and members of Congress.
If members of Congress, no matter party, are unwilling to actually impeach those who support their ideology to maintain freedom for all citizens and not just a select few, you have in place opportunity for corruption and defacto dictatorship.
The founders imagined that the threat of impeachment would be sufficient to keep people in line, but we now know that is not true. Impeachment itself is useless without conviction. If Senators are unwilling to convict a sitting President for inciting an insurrection, then for what will it ever convict a President for?