You did not need to file tax returns for 2021 and 2019 and you father could still have claimed the tuition credit using $4000 of the tuition for 2019 and $2584 for 2021.
The 2019 math is:
$10,774 Scholarship
- 5425 Tuition
= 5319 Excess scholarship
+ 4000 of Tuition used by parent to claim tuition credit
= $9319 Taxable scholarship
Since that is less than the $12,500 filing requirement, you are not required to file a tax return. BUT, you may want to file one anyway to document the justification for your parent claiming the credit
The 2020 Math:
$20,397 Scholarship
- 6636 Tuition
= 13761 Excess scholarship
+ 4000 of Tuition used by parent to claim tuition credit
= $17761 Taxable scholarship
+ 1500 Wages
= 19,261 Total income. You must file a tax return. You are still a dependent of your parent, despite the high income. This is because scholarships are disregarded for the dependent support test (despite being "income").
New wrinkle: Box 7 on the 2020 1098-T is checked. This might mean that some of the amount in boxes 1 and 5 may be needed to be allocated to 2021. The 1098-T doesn't tell you how much. You would have to know that from your own financial records.
