There is a solution to this, but it’s not one that any company is moving towards in any meaningful way. The answer is twofold:
1) hire humans to moderate content.
2) PAY & SUPPORT THEM WELL.
I used to do forum moderation professionally (for an actual paycheck from a corporation) and was severely under-paid. One of the companies I worked for even explicitly stated over and over again how important their online community is to them, and…still paid me half of what their lowest-paid salesperson was making.
Patrick is right, the algorithms will never ever be perfect (or even come close) and there is a massive need for oversight by trained human moderators.
But why would anyone ever want to be one?
Doing moderation is a very tough gig that can take a huge toll on your mental health, especially if you’re struggling in any other areas in your life. Combine that with extremely low pay, and leadership that doesn’t understand what you do, why it’s important, or (crucially) how you contribute to the bottom line and you have a situation where even if your company does have some sort of moderation position you’re given no support of any kind, have no room for advancement or pay increases, and no say in what needs to be changed within the product to support better moderation.
Companies think so little of moderation that they frequently outsource their moderation, allowing them to offer even LESS support and pay to moderators that are exposed to constant horrible abuse.
We need a huge overhaul and revamp of the way we think about moderating internet content. We need to treat it as a viable career path, with standards and guidelines and mentors. We need a moderator union that offers support and resources (considering that state of unions in general in the US, this is an even long-er shot). We need huge internet companies to understand that their platforms will no longer exist if they don’t invest in better moderation and act accordingly.
Until those things happen, anyone who has any desire to be a professional moderator will burn out. There’s a reason there are no “expert moderators” that companies consult for training, they don’t exist.