The dollar value of points you earn that are based on spending, on either a SoFi debit or credit card, are not taxable income.
The dollar value of points you earn that are not based on spending (ex. points earned for logging into the SoFi app) are considered taxable income by the IRS.
If the dollar value of points you receive, when combined with payments received in connection with other SoFi products (ex. Referral payments for SoFi loan products), is $600 or greater in a single calendar year, SoFi will issue you a 1099-MISC reflecting the amount of taxable income. This information will also be reported to the IRS.