Sharingd showing up on activity monitor and using 6mb resources

The naming follows a Unix convention for background server processes. sharingd is short for sharing daemon. The system may be restarting this every time that it dies because

1. It is programmed to always have one of these processes running (to be ready to respond if you enabled sharing), or
2. Because it handles sharing services of some kind that are still enabled, like ones that provide integration between Apple devices (Macs, iPhones, iPads, etc.).

This is what I see if I issue a 'man sharingd' command in Terminal under High Sierra. The list of functions that the daemon handles may have grown in later versions of macOS.

sharingd(8)               BSD System Manager's Manual              sharingd(8)

NAME
     sharingd -- Sharing Daemon that enables AirDrop, Handoff, Instant
     Hotspot, Shared Computers, and Remote Disc in the Finder.

SYNOPSIS
     sharingd

DESCRIPTION
     sharingd is used by the Finder to enable AirDrop file sharing, Handoff
     between iCloud devices, Instant Hotspot discovery, connecting to shared
     computers, and accessing Remote Discs from other computers.

FILES
     /usr/libexec/sharingd

HISTORY
     sharingd first appeared in Mac OS X 10.9 and iOS 7.

Darwin                           June 7, 2023                           Darwin