It is not prohibited for the charity to also share in the annuity or unitrust payment, but the income tax deduction is not increased. The ability to personally allocate assets to help, say, blind children, should be something of value to you. If you cannot say that passing the remainder of the trust to charity has value to you, then the CRT may not be for you. On the other hand, it is possible that the financial pluses of the CRT will outdistance the minuses even for the person with little or no donative motive. The biggest minus of the CRT, from a purely financial standpoint, is that there is a charitable element.
Assets pass to charity rather than go back to the donor or the donor's family.
The principal reason that the financial benefits may even exceed the charitable sacrifice is that the CRT itself is usually tax exempt. For this reason, the stream of payments that come out of the CRT to the beneficiary are enhanced. If you envision two runners approaching the tape that marks the end of a race, and the race is close, and these two runners are the citizen and the government, the government basically wins. If it is a photo finish, normally you don't even have to look at the photo. As a general rule, Congress writes rules that resolve close issues in its own favor.