Recently I tried to get Twitter for the first time and my gosh what a mess that platform is. I only wanted it to follow some researcher to get up-to-date research topic but the damn app just have to fill the feed with "retweet" and other tweet I didn't even ask for (and I can't turn this off!)
If you submit a resume to a recruiter they can submit on your behalf to a company. If you submit to many in the same firm some will use the date received in order to assign any money earned.
Without this rule you would have people sending in resumes without the person's knowledge.
But LinkedIn is basically fine as a way of keeping track of people and potentially contacting those you're not directly connected to elsewhere. I go through my connect requests once a month or so and ignore about half of them. I ignore any messages trying to sell me something or recruiters that are pitching something that's not remotely my thing. (In all fairness, my profile isn't really filled out so it would be hard to know what I actually do or have done.)
I do similarly with respect to notifications which is a good rule of thumb in general.
Maybe ban it in hosts and unban when needed?
If you want to use LinkedIn and keep your sanity, I suggest disabling all notifications except the email notifications for new messages and then don't log back in unless you get an e-mail and you need to respond to that person.