unions

It wouldn't necessarily be as simple as an income tax but I'm sure we can figure it out. One idea off the top of my head is you could create a VAT that assumes a product is completely created by robots and then companies can deduct a workers salary from that tax. Not saying that's perfect, just one example off the top of my head.

Service industry is trickier, but you could come up with a minimum wage tax per machine for machines that directly interface with a consumer, so a self checkout robot would be treated like a minimum wage employee or something with the special factor being that the consumer directly interacts with it. The POS industry is already regulated so I think there's a natural place to target that tax on.

I don't think it would be simple or easy, but our tax system was designed around economic output of humans and didn't take robots into account so if we don't try to make changes to it we're giving an unfair advantage to robots and punishing humans for being human, which is not a good situation and I don't think it's sustainable into the future. Hard or not, it's a problem I think is critical to be solved for society to function as automation becomes more and more versatile and ubiquitous.