Everybody have a lot of addresses for multiple crypto currencies on wallets, exchanges etc
It's annoying because you must open the wallet/website everytime and you can get confused if you do it frequently.
To fix that, there is Hodle.me which allow you to store or share your addresses online and get access to it in one click.
It's the "best way" to lose your privacy, people will know all your different crypto addresses
this is a great site for listing crypto addresses but not intended for what you said in your post
if you just want to keep track all your crypto addresses, do it a simple way with a text file
The purpose of the website is to share the addresses you'd like to share in order to receive donations per example to support a project or a cause, a lot of websites like wikileaks or influenceurs just write down all of their crypto addresses somewhere in their bio to receive a support from their traffic, now you just have to share a link.
now, that's a better understandable use for the site that I can agree with