This is actually the main core of the problem and it really hearts to watch nvidia deliberately igonre the dxr driver support for the 10 series to achieve more money from selling their RTX card , am not blaming Epic for this but at least they should support their users with the minimum effort even by informing their users about this so at least everybody will know what nvidia is doing , the prices of the 10 series are dropping down because of this and it will increase the 20s series just like the miners did , and at the end only those who can afford to buy an additional RTX card or sell their 10 series for less then their original price just to catch up with this.
i understand that RTX is much more faster in raytracing but atleast help us develop it and test with our slower 10 or olders series