It wasn’t the same thing, all three of them were different plans using different justifications based on different laws. One was a blanket forgiveness based on laws allowing for adjustments of student loans in emergencies. One is need based or other circumstance based forgiveness based on a much earlier law giving the department of education wide latitude to make adjustments. And one was adjustments to the income based repayment plans based on the laws establishing those (this has happened many times in the past, such as the establishment of the PAYE and REPAYE plans).
It’s especially egregious that judges are blocking the SAVE plan, as many similar adjustments have been made to income based repayment plans previously with no one taking any issue.
Unfortunately the interest rate is specifically set by law and tied to 10 year treasury bill rates. This cannot be altered with an executive action, would need congress to change the law.
https://studentaid.gov/understand-aid/types/loans/interest-rates#who-sets
That’s why the executive orders are focused on things like minimum payments, how long it takes to get forgiveness, who qualifies, etc, because the laws give the department of education more latitude to adjust those things (or are supposed to at least, weird rulings from republican judges notwithstanding).