Charlie Giancarlo wrote:
Does anyone have any idea why so many files might have been created and not automatically removed by the system?
I have been using Keychain since its introduction with no issue...
Keychain is the password management by Apple. It was introduced ~1999 with OS X 8.6, and has been included in all subsequent versions of the operating system.
In these Apple Support Communities I have never heard of this issue before over the same time period— so not much help there either..
Here is a typical Keychain folder for comparison

If there is third party interferences— you can good look at your System config. and reveal conflicts or issues, you can download/run this trusted utility https://etrecheck.com Allow the Full Disk Access for best results.
If you need help interpreting the report you can post it here in its entirety in the "Additional Text" box in the editing toolbar below, in your reply.
Typically the Keychain works trouble free with the login Keychain left unlocked:

ref:
What is Keychain Access on Mac? - Apple Support
Keychain Access User Guide for Mac - Apple Support
Manage passwords using keychains on Mac - Apple Support
If you need to update your keychain password on Mac
If no insight or resolve I would encourage you to Call Customer Support (800) MY–APPLE (800–692–7753)
or on line Apple Support
Outside the USA—Contact Apple for support and service by phone
See a list of Apple phone numbers around the world.
Contact Apple for support and service - Apple Support