The worry is that such distancing increases the risk of collateral damage, or simply mistaking of targets. There were accusations during the wars in Iraq and Afghanistan, that the US were bombing weddings and civilian homes.
It seems to me collateral damage making the news is a big improvement over the old days. In the past, when giant armies clashed, entire cities were razed, the countryside left barren, huge populations were displaced, women and children enslaved, etc. Now it's a big deal when a single wedding or child is hurt... what used to be so commonplace as to not even be worth mentioning now makes headlines. That's an improvement, isn't it?
The ability to perform "surgical" assassinations with precise targeting should be overall less damaging than rolling in with tanks and napalm and carpet bombs.
IMO the "facelessness" of drone war is sort of virtue signaling... why should it matter whether you can see your opponents before you kill them? It's not like you're giving every opponent a fair trial with a jury before you kill them. It's war. More precise targeting of a smaller number of targets, even with a higher error rate, should still end up killing fewer people overall than an indiscriminate total war.
Now, more selfishly, from a US national security perspective: When we're expecting big powerful states again as opponents (as in, China or Russia instead of Afghanistan or Iraq), frankly, we'll need all the help we can get. It's one thing to mourn innocent Afghan civilians lost during a small-scale conflict, it's another thing to be ill-equipped to handle the bigger threats of the future against enemies who aren't at all concerned with human rights.
I don't think it is realistic to expect a peaceful, utopian future for our species in the near-term. All signs point to conflicts escalating as resources diminish, democracies wane, authoritarianism rising, and climate change exacerbating divides. As cold wars heat back up and proxy wars proliferate, we'll either be sending in more technology or more troops. Personally, I'd rather it be American drones than American lives.
Targeted drone strikes are at least somewhat less brutal than WW1-style trench combat or hand-to-hand melee combat with swords and spears. Wars in general are getting more precise, with fewer fatalities, over time (https://ourworldindata.org/war-and-peace). For all this talk of killer robots, the Rwandan genocide killed more with machetes than our drones.
Is it necessarily a bad thing that we're replacing boots on the ground with robots in the air? Eventually, one would assume, our opponents would catch up as well, and maybe at some point in the future, battles will be more drone-vs-drone than fighter pilots dogfighting it out. Our killer robots against theirs.
Maybe wars are getting more high-tech, but if their body counts are lowering, isn't that a good thing?