What do people need to sync their iPads to desktops for? I use the cloud for everything
Many reasons, at least a few that I know are:
Because cloud costs money after a tiny amount for free, and committing to pay for online storage in perpetuity isn't cost effective.
Because cloud is not very secure. If you are in a field that has strict data security requirements, like medical, law, finance, or government, then storing PII or other similarly sensitive files in dropbox or the like is downright negligent, but properly secure cloud storage services are very expensive.
Because sometimes you need your files offline.
Because making a backup of files in cloud storage requires a desktop/laptop anyway.