why is standard deduction $7041 and not $14,600 filing single

If you are a dependent and your taxable income is less than the Standard Deduction then your taxable income is used.

This happens when you file a tax return as a dependent of another taxpayer.

If you can be claimed as a dependent by another taxpayer, your standard deduction for 2024 is limited to the greater of: (1) $1,300, or (2) your earned income plus $400 (but the total can't be more than the basic standard deduction for your filing status).