My critique is not due to pessimism, it is due to afactuality. Breakthroughs in science are plenty in the modern era and there is no reason to expect them to slow or halt.

However, from your later comments, it sounds as though you feel the only operating definition of a "breakthrough" is a change inducing a rapid rise in labor extraction / conventional productivity. I could not disagree more strongly with this opinion, as I find this definition utterly defies intuition. It rejects many, if not most, changes in scientific understanding that do not directly induce a discontinuty in labor extraction. But admittedly if one restricts the definition of a breakthrough in this way, then, well, you're probably about right. (Though I don't see what Mars has to do with labor extraction.)