I don't wish to pile on too much in this thread, but circling back to the concept that an Admin has to approve someone's exit from the project/account.
I might be able to accept this if you are still working for the company that is also working on the project. As in my case where I am no longer with that company, then I should 100% have that option and control to remove my profile from the project/account.
I'm sure @daniel.nc.gijsbers was likely only joking in their previous reply, but let's use that thought as an entry into an analogy, like a cloud services email newsletter/subscription.
BIM 360 has an email notification system, which at most will email you a daily update for items you are assigned to, and becomes more frequent when the item's assignee is the company name to which you are/were attached to. But unlike a traditional email newsletter, BIM 360 has no way for you to completely unsubscribe, or to turn it off in your project profile Notifications settings.
So even when you no longer have any connection to the company that is working on the project, you may continue to receive email notifications in your personal profile that was formally used for work. The closest equivalent of this is email spam with currently no way to unsubscribe.
I'm no GDPR expert, but I do believe the ability to unsubscribe yourself from emailed material is a requirement.
So I feel this topic goes beyond a nice-to-have feature, and steps into the legal depths of personal data and privacy compliance, especially in certain regions around the world. That should make this a fairly high priority to resolve.