You have to tax something that they are doing that an individual is not. If you tax "all compute" then they're just gonna pull the same shit they do with straws and blame the individual.
You have to tax the action that is replacing a human worker. If a human job is displaced, it gets taxed. Want to AI generate some massive image through prompts? How much would it take a human to complete the job? Take some % of that, and charge it. Play it somewhere along the lines of "Intelligence deserves pay", and since it's artificial intelligence - it doesn't have rights to spend its own pay (or the need to) so put it into a universal income fund.
We're reaching a post-scarcity society now. We should be making lives easier for everyone.
Being written in C++ doesn't keep it from being reverse engineered in exactly the same way. All code can be reversed. It's a little easier with Java because java isn't turned directly into machine-code at compile-time.