Multiple experiments to detect dark matter directly here on earth have been constructed. They expected a handful of detections a year given the estimates of local dark matter densities. Those experiments have not yielded any detections. This sets very restrictive limits on candidates for particle like dark matter.
I'm fully aware of astronomical observations that suggest the need for dark matter. That's not what I was referring to.
So far, astronomical observations are all we have, the lack of terrestrial observations have only been able to elliminate candidate particles, not measure them.
I'm still waiting for hexagon monitors as they are clearly the bestagon.