

It’s not about defeating tracking of yourself, but who you share the link to, your relationship with them.
Without that tracking parameter, if the URL is common among many people (which it usually is, since usually one thing has one URL for everyone), then it’s impossible to know who shared to who.
If you have the tracking parameter, then the service can know that you shared the URL, as well as who you shared it to, being able to put that information together and thus built more of a profile on your social connections.
I’ve got backups. Haven’t updated or looked at my server in months. If I’m ever compromised by missing security updates, I just load a backup and regenerate all keys.
I don’t put any critical data on public facing servers.