Earlier quoted context omitted.
You will get dominated by bot-generated spam at the very least. The bots don’t care that their content will be seen by one person, they just hammer every form they find, and the recipients will be overwhelmed having to delete this, and they will criticise your platform. As well as bots, you will get people manually hitting it. They’ll often use software customised to spam you. There is zero chance this model survives…
I am flattered. Let's say my platform somehow get popular, and bots is hitting it for no financial reason at all, they still get the one reply per node limit. Also I have a global per user replies limit per day. If you have an orchestrated army of bots hitting me, then I would get DDoS'ed, just like everyone else. However, that has nothing to do with content moderation at all, right?
I've gradually built my setup to filter based on words, URL fragments, block IPs, honeypots, shadowbanning, etc and they still get through. Take away all content moderation and I would be overrun to the point that my site was useless to my users. Those sort of methods are the easy bits too; dealing with greyarea trolls is the worst.
Good luck. You'll find out.