bacteria, fungus, plants, protozoa, and (arguably) viruses are all alive, too. bed bugs. rattlesnakes. being alive isn't actually that special, nor a reason, in itself, to refrain from eating or killing that thing.
tehy also weren't stuck with trump-vs-trumplight for 60+ years as their only options. voting for trumplight and getting trump seems like it should be a probable outcome, and having better options to begin with seems like a better strategy than hoping full-fat trump isn't selected. of course there's also the problem that the democrats have been complicit in concentrating power in the executive for that entire time, so when someone gets in and uses the power in a way they don't like (or pretend not to like), tehy really only have themselves to blame.
other societies have prevented trump-like figures from seizing power. we could look to them for the kinds of things we could try. or you could keep feeding the same machine that made trump in the first place.
from my perspective, it is the same strategy that created a political climate in which trump could be effective, and has failed twice now to stop him from seizing the presidency.
voting Harris didn't reduce any harm, but it did prevent real alternatives from gaining traction.