Isabelle -- I tend to delete most of it, too. So many times, one opens a profile, only to find several screens of nothing. For example, there'll be a list of a dozen or more jpg images that exist, somewhere, but were not uploaded with the profile. Gone!!
I am not one of those who thinks the more you have, the better. I like to keep it short, with links in case someone wants to look more deeply. It should not be a 10-minute treasure hunt to try and locate if there's (say) marriage information buried in there somewhere. Plus there's all that GEDCOM-specific information that is 100% irrelevant like User # or most recent changes. There can be privacy issues, too, with email or home addresses included. There's often very little worth keeping, but you have to look in case it mentions a Census record or book or something.