It is safer in the sense that, when you selfhost, you have to take care of your own backups. You have to make sure your data is still there, even if two hard drives fail, or your house catches fire and your server burns down. Hertzner is doing that for you.
But you are right of course, from a privacy standpoint it would be much better to have your data on your own server and only send encrypted backups to a remote server like Hertzner.
I started with 30, so not far off. My first step was to try to daily drive Linux. Best decision ever, working with a computer suddenly was fun and exciting again.