How do I enable Simple Finder in Big Sur

You are probably correct, I know it was in Versions 8 and 9. Are yo uaware of a third party substitute? Even earlier, Apple offered "At Ease" which allowed the creation of a very simple "button " interface for the Mac. With it I could set up my Mac for the grandkids to ply games, knowing it was safe from mischief! I also used the network version in school computer labs.

Our very small Historical Society has finally been able to get a decent computer that will need to serve mutiple functions. I will be a repository for digital documents, keep our business records, but we will also need to make it available for public clients to use our Ancestry.com account for geneaological research, review digital documents in our collections, etc. We need to both lock guest access to read-only but would also like to replace finder use with a menuing system, as we were able to do with the Apple "At Ease" product that ran on Macs running MacOS 7.5 thru (I think) 9.2. I don't know if you are familiar with "At Ease" but I used it in several school computer labs. It worked well on Appleshare networks.

In use, a guest would be presented with a simple multilevel menuing system that would take them to various available resources. The first Menu screen would just have broad categories such as People and Families, Business and Industry, Religious Organizations, Local Events, Etc. A person who selects "People and Families: would be taken to a sub menu where they could select a name or family and be presented with perhaps another menu or hypertext document where links could be selected to lead them to a newspaper article, an obituary, a video or audio biography, etc. Another choice from the main menu screen could be "Collection Database" which would open a searchable LibraOffice database of our collections.

Staff, however, would be given full Finder access.

I hope this gives you a general idea or what we are after.