If things get automated so much that a company ends up being a few guys in suits collecting the profits while the robots do the work, the governments might as well expropiate it. At that point, whatever the company does has been trivialized so much that the usual advantages of the private sector (competitiveness, etc.) become moot. If it also creates no jobs, there isn't really much to lose for the state (and thus its citizens) from expropiating it and using the profits to give citizens a living wage (be it for working or just a guaranteed wage like an UBI).
And then there's no need to tax the robots, the money goes to the state anyway.