While working I handled the investments and did reasonably well. When Spouse retired (I had retired 6 yrs earlier), I turned the portfolio over to the independent CFP firm that we had selected some years earlier to handle MIL's portfolio. We wanted a multi-generational firm as our heirs are not experienced in handling a large asset portfolio nor in dealing with the tax/legal issues of eldercare (we have no children).
The biggest difficulty in finding a top-notch independent fiduciary manager is.....finding one. The better firms don't do 'hard' advertising; they get the vast majority of their business through personal and client referrals, which is known as 'soft' advertising. Unless you know someone who is a practicing CFP, you will never hear about the firms who win awards for excellent customer service and knowledgeable staff.
As I have related before, I was fortunate to work for a short while for a semi-retired, independent CFP, from whom I learned a lot and respect immensely. He goes the extra mile for his clients and if he had a younger partner to inherit the business, I would have been happy to use him as MIL's and our investment adviser. Unfortunately he did not, and instead we asked for referrals to three firms we might use.
He was glad to help us and called the head of each firm to introduce us and say we were interested in interviewing them. This personal referral was why our account (which is now the combination of deceased MIL's portfolio and our own), although relatively modest in worth, is handled by the senior managing partner and founder of the firm, who is now counting his 40th year as a CFP.
It's actually too small and simple for him to be our rep; normally our account would be given to one of the younger CFPs (they have seven total, in addition to operational staff). My spouse laughs and says it's because the partner and I get along like gangbusters. When we meet, we spend about 15 mins on our account and then an hour or more talking about global financial news and geo-political trends!
We have a moderate risk profile, with a 60:40 AA. Our distributions are handled in a tax-efficient manner, something that is important to us. It was on the advice of the firm that we set up a DAF a few years ago, as our charitable contributions were growing in size. Spouse is reaching the age where QCDs can help reduce the tax burden of his RMDs, since we don't need the money and the Trump tax cuts may sunset soon.
I still make the financial decisions, and it's nice to have that 'neutral third party' resource available - not just for our questions, but for our successor trustee and heirs.