LinkedIn is useless for managing your contacts. Try finding out who you met a year ago today at a particular event, or try exporting everyone's vCard including email addresses.
It has degraded to a social media spam site where people self-praise completion of "introductory walking and breathing" on Coursera.
Important: never conduct a confidential chat there (because they can never be deleted, in case one day there is a breach), always take conversations to your email immediately.
There is a need for a LI-like tool that actually offers what professionals need, but it's not LI (and the fact that it is owned by Microsoft does not help).