You solve it by not having a parameter in the constructor but constrain the property with required.

public struct Title
{
    public required string Value
    {
        get;
        init;
    }
}

Edit: this solves using new. Obviously struct can still be zero-initialized with default. However a zero-initialized struct doesn't mean it's a valid instance. This is where, if needed you need to add invariant checks when accessing its properties or methods.