Conventional lenders won't accept gifted equity as a downpayment. Heck, almost no commercial lenders will allow it either. The concept of collateral is really lost at that point.
If your parents sell you their home for $100,000 and it's worth $300,000, their gift of equity equals $200,000, the difference between what they're selling the home for and how much it is actually worth. A gift of equity is valuable.
Potential tax implications For example, each parent can give each child up to $18,000 per year in 2024 without the gift counting against their lifetime exclusion. Amounts over that will be debited against the federal gift and estate tax exclusion limit.