Utilitarianism, taken as a world-historical arrival at the level of civilization itself, might very well have a net-negative utility. It is perfectly plausible that an overly refined awareness of, and sensitivity to, utility would have unintended consequences tending toward catastrophically negative outcomes. Deontological ethical systems have often issued from this intuition, I think. Below are the moving parts to this argument.
Our awareness of all the suffering that might be alleviated has recently exploded due to the information revolution. We still have no idea what this will do to human beings in the long run, but it sure seems plausible that it increases the prevalence of guilt feelings and anxiety about a nearly infinite number of global problems. Incentives exist to highlight and report these negative stimuli, and incentives exist to publicly feel bad about them; it strikes me as perfectly reasonable to imagine that globalized modern civilization is already headlong into an irrecovable spiral of collective depressive delusion. While a utilitarian spirit is obviously not the only or even main driver of this dynamic, it is a a necessary condition for it. The counterfactual — large numbers of individuals switching to a deontological worldview in which they’re only felt sense of obligation is to a small number of categorical local rules — would almost certainly increase global utility to an extraordinary degree. Unless you think the utilitarian reflections of the average person cause them to non-trivially improve the world. With respect to the overwhelming majority of people, this strikes me as unlikely.
Our intuitions and institutions get updated slowly. We suddenly understand many sources of suffering way better than ever, but nobody can change all of our institutions to solve these problems at anywhere near the rate our conscience would need to be be at peace. Therefore, the contemporary global village is plagued with a necessary temporal gap between the suffering that exists, and our ability to reduce it. If you consider the fact that our sense of ethically problematic suffering increases rather than decreases with progress, it is possible that this temporal gap increases even as we make technical progress closing it. Again, the more effectively utilitarian we are, the more felt suffering might increase, precisely as we objectively decrease suffering and increase net-utility with respect to most direct measures.
How great is the suffering caused by this gap? That’s anybody’s guess, but it does not seem implausible that it is greater than the entire history of utility gained by human activity heretofore.
If you doubt that the suffering caused by hyper-awareness of suffering could be so large, here are some reasons why you might not want to dismiss this idea. Human experience is recursive, so it seems to me that this makes it potentially exponential, non-linear. If you’re depressed, you feel guilty for being depressed, then you feel stupid for feeling guilty for feeling depressed, all of which makes you more depressed, and so on. Human experience can rapidly approach infinities of low, and high. I see no reason why human suffering could not potentially skyrocket toward infinity given media-driven negative information glut, instant interconnectivity at large scales, and economic incentives to spread and express sad affects, not to mention cognitive bugs such as negativity bias). None of this dismisses the wealth of data marshaled by people such as Steven Pinker, showing that in so many ways, markers of human suffering are decreasing. Felt perceptions might be wildly miscalibrated with objective data about world trends, and still veer off in an explosive detachment from reality.
Additionally, even if you don’t think that’s possible, a small number of highly suffering people can still wreak untold havoc on society at large. Trends such as anti-natalism and anti-civilizational thought more generally, often promoted by sad people who want to wind down life itself, are to some degree children of utilitarian progress. They look at the costs and benefits of humanity thus far and (however miscalibrated) they decide none of it is really worth it, and they speak and act accordingly. This is perhaps because, in the long run, there are no costs and benefits, and thus the validity of deontology gets revealed with particular clarity in end times. Regardless, if anti-life intellectual currents were to produce future policy changes, or some new, crazier version of these thought-patterns were to take hold in the form of the next big moral panic, which in turn leads to centralized policies with negative systemic effects, some portion of these consequences would have to be counted as causal effects of a short-circuiting utilitarianism. You can say that such ridiculous deductions from the utilitarian starting point are unfounded and you might be right; but you still have to chalk-up such consequences as effects of the utilitarian memeplex’s diffusion into the postmodern polity.
The utilitarian ethical defaults of modern western individuals are in meltdown from overheated inputs they do not have the capacity to process. Cooling innovation always follows hot invention, but we live in a unique historical period where the time lag between new inventions is less than the time lag between one invention and the secondary technologies that make it work over time. Fires are no longer put out, but displaced by new fires, which burn only long enough to sustain a feeling of continuity before the next fire arrives. Calculating net effects seems reasonable when it is possible to imagine a shared world; as human worlds divide, collapse, and revivify differentially, efforts to calculate overall effects on a shared world will be increasingly painful. Deontological ethics receives its final vindication on consequentialist grounds.