>>Where will they get those resources for themselves? From the job that they don't have anymore, because of AI?

From goods and services they provide to others - now at lower cost.

>>There is no reason to assume that the AI employment catastrophe will end with coders.

It will not. It will also create a lot of new jobs. Stuff will get cheaper which means you will need to work less on average to sustain the same standards of living.

>> Instead of paying programmers, they'll pay the owners of data centers.

Yes but less. Paying less means more is left.