Can I use the Qualified Charitable Distribution using the Fidelity Charitable fund? Is it better than a non QCD gift deducted as an itemized deduction?

No.

You cannot make a QCD gift, from your IRA, to a donor advised fund (like the Fidelity Charitable fund). It simply isn't allowed, by the rules. Instead, you must make your QCD directly to the charity. 

Reference: https://www.irahelp.com/slottreport/ten-qcd-rules-2019-you-need-know

"The QCD rules are not available for gifts made to grant-making foundations, donor advised funds or charitable gift annuities".

May I ask what "rules" do not allow this?

<a rel="nofollow" target="_blank" href="https://www.fidelitycharitable.org/philanthropy/qualified-charitable-distribution.shtml">https://www.fidelitycharitable.org/philanthropy/qualified-charitable-distribution.shtml</a>

The distribution must transfer directly to a qualified charity. "Qualified charity" is an official IRS designation. The list of qualified charities includes all 501(c)(3) organizations; and the list explicitly does not include donor-advised funds, foundations, or other grant-making organizations.

It's the law.  Section 408(d)(8)(B)(i) explicitly excludes donor advised funds (described in section 4966(d)(2)) from being eligible recipients of qualified charitable distributions.

Thank you.

Thank you for the detailed answer.

Thank you for the detailed and referenced answer.