But hasn't the concentration you're describing been created under the current copyright system? Those winning from this system appear to be exactly those groups that are concentrating power the way you describe.

Currently there is little concentration compared to what it would be, without copyright you would have a single big corporation where people get all their content. You either get paid by them to create content or they distribute your content anyway without paying you. Under such a system no way youtube would pay creators 55% of revenue and so on, big corporations gains way more power when you remove copyright.

That wasn't much of a problem before copying was so cheap and easy, but today that would absolutely happen.

We need a special AI tax. Profits made by foundational models (not the application layer) get an additional tax.

We're entering a new paradigm that copyright is not sufficient to handle. These AI models have sucked up the output of humanity itself, the entire commons. The public vs private distinction isn't that important. They're going to cause job losses across many fields, so we need a new solution. Relying on the court system to enforce copyright claims for the benefit of a single claimant is not a solution that scales to solve the actual problem here. Another thing is, foundational models are prone to monopoly because the barriers to access compute are so steep.

The barrier of entry to building a "foundational model" is less than $400 of compute time (72 hours) on a handful of rental A100 using widely available open source data sets. Open source projects by ICs are already on par with GPT3. It's gonna be really hard to regulate stuff in its current form, which is already commercially beneficial

I can think of several large organizations who would love small AI companies to be pushed out of the space with a tax.

No. These are profits on foundational models. Small companies playing catch up don't make profits on foundational models.