I handled our finances for decades until I finally got tired of it. Plus, we were getting nearer to retirement and I didn't want to deal with the tax decisions (not that they're that hard, but it's yet One. More. Thing.).
I used to work for an independent CFP so when my MIL sold her home and came to live with us, I asked him if he could recommend a firm that would "fit" her profile. She had a high six-figure account but was already diagnosed with mild to moderate dementia. Absolutely NO financial acumen at all. We are childless so if anything happens to us, she had no one else suitable to advise her.
He is semi-retired and a 40-yr veteran of the industry so has all the local contacts. He gave me three recommendations, so I had four referrals including his firm. All were firms that do no "hard" advertising so virtually all their business - 95+% - comes from client referrals.
We researched and chose one of the firms. Because we were referred by my ex-boss, it's the firm's founder who handles our accounts. We're probably the smallest account he does handle, LOL. The firm has been in business over 25 yrs and did an excellent job for her. They work in tandem with our tax advisor and estate attorney.
When DH retired, we chose to move his retirement account to the same CFP firm. Yes, we pay advisory fees. However, we have been very pleased with their performance. More importantly, because our own estate (which now includes MIL's assets, who passed on 2 yrs ago) is a healthy size, our own heirs also have the disadvantage of knowing virtually nothing about how to handle a 7-figure portfolio account, not including the RE and personal assets.
If we were disabled, our heirs know zip about dealing with pension, SocSec, and our long-term care insurance policies. They would struggle with the tax situation. IOW, they would need help in the form of reliable fiduciary advice, but would have no way to effectively find it.
Thus, we are comfortable using a firm to handle our investments - not for the biggest/best returns, but for the inestimable benefit of being able to rely on reputable fiduciaries to help deal with issues our heirs are unfamiliar with, having never faced them in their own personal lives.