Pretty much every mainstream platform at least provides the possibility for the administration to be aware of the contents of private messaging. This is not just unique to this forum, or other forums, but is especially true for large platforms such as Instagram, Facebook, and other private messaging software. Whether that is actually used by respective administrations and moderators is another aspect of this issue.
I think you got your idea from letters, and you are right about that. In that context, around that framework, it would be illegal for anyone other than the sender and recipient to open the contents if not in all countries, then at least in most. Although that too has its limitations. For example in cases of investigations by officials.
I have been on forums (and in the past, chatrooms) for years. On at least one of those, it was said that PMs were vieweable by only the participants, so that's where I got this from. It's quite a sticky topic. Off-forum, off-ToZ websites, people are responsible for themselves. On here... it's difficult...
You naturally display competency in these areas, or if you did not, you would be able to learn it. By nature of our current world, Mercurial skills are in demand, including for ToZ projects. It is better to try and learn than never do so, as if you had started 1 year ago, then you would be an experienced veteran of these projects and able to direct new people, perhaps.
Just from what happened in the past, I feel you may be hung up about your place here and that could be a deeper reason that is making you avoidant. Regardless, these positions are still open, but you have to be willing to involve yourself, including resolving obstacles which may upset your ability to do otherwise good work.
Thanks for your reply.