Are there professional conservatorship trustee services for elderly individuals with no family/friends to assist with management of assets?

In some states there are state funded guardians/fiduciaries. In other states they are allocated by county. Often more people in need of services than there are slots. Contact area on aging or elder services to find out more about your state.

There are Licensed Certified Fiduciaries. Speak with an elder law attorney who typically deals with Fiduciaries as they are appointed by the courts to manage for elders without family or with troublesome family situations.
In California the PFAC or Professional Fiduciary Assn of California has an email at pfac-pro.org and their phone is 866-886-7322. They could likely connect you with the infor. for your own state. There are also professional bill managers CDMM Certified Daily Money Manager at secure.aadmm.com/find-a-dmm.
I hope you will connect with someone who can help. If this is a sizable estate I would go directly to a Trust and Estate Attorney. They can recommend someone and may in fact do it themselves. Banks can also be helpful with this information.

Start by contacting a CELA certified eldercare attorney.

You are looking for a fiduciary.