Given how long philosophers have been at conceptual analysis (I mean the 20th century stuff), and how many have been doing it, what can we say are the two most important concept results of all that effort?

It seems that the brain has a "small world" architecture - or at least the cortex does. Everything can connect to everything else in a few synaptic steps.

Many philosophers in the second half of the 20th century really seemed to think that they were laying the foundations for science by laying down the conceptual (necessary) truths.

Knowing about the neurobiological and evolutionary basis for social behavior can soften the arrogance and self-righteousness that often attends discussions of morality. It may help us all to think a little more carefully and rationally.

Early studies of sleep and dreaming were crucially dependent on waking subjects up during sleep to find out whether they are dreaming or not. Using that strategy, it was found that when the eyes are rapidly moving (REM sleep) people are usually dreaming; when the eyes are not moving, there may be some mentation, but little in the way of visually rich dreams.

It seems probable that humans have been on the planet, with much the same brain, for about 250,000 years.

Humility bids us to take ourselves as we are; we do not have to be cosmically significant to be genuinely significant.