Why gravitational waves, which could be inferred as related to dark matter interactions, are not yet detected by LIGO/VIRGO instruments? LIGO/VIRGO instruments are functioning already for quite a while and since then they captured already quite a few instances of gravitational waves which were inferred as products of interactions such as: 1) mergers of black holes; 2) mergers of neutron stars; 3) mergers of black holes with neutron stars;
Given that in total the mass of the dark matter is assumed to be  much greater than the mass of the regular matter, why gravitational waves, which could be inferred as related to dark matter interactions, are not yet detected by LIGO/VIRGO instruments?
 A: Black holes and neutron stars are (part of) "dark matter" - in that they are not easily seen/observed. However, if they formed after the big bang then they are only examples of baryonic dark matter. But we think (based on for example the combined analysis of the cosmic microwave background and primordial nucleosynthetic abundances, and large scale structure simulations) that most of the dark matter in the universe needs to be non-baryonic. Thus (non-primordial) black holes and neutron stars are not considered solutions to the dark matter problem.
One thing that non-baryonic matter isn't very good at is clumping together. To make compact objects requires the dissipation of energy and loss of angular momentum, and non-baryonic dark matter can't do that because it doesn't interact electromagnetically with itself or anything else.
But to efficiently produce the power and frequency of gravitational waves that aLIGO detects requires closely separated stellar mass compact objects. Since you just can't form these out of dark matter and the non-baryonic dark matter is thought to be sparsely spread in huge structures surrounding galaxies, then the gravitational wave sources observed are unlikely to have any connection with dark matter.
As an aside, since dark matter does interact gravitationally and gravitational waves are a purely gravitational phenomenon (for merging black holes), then it isn't clear there would be anything different about gravitational waves from a pair of merging black holes made of dark matter in any case.
Edit: I see you mention primordial black holes in the comments. These, if they exist, would be classed as non-baryonic dark matter. They would likely be of much lower mass than the LIGO-detected black holes and so would not be powerful sources of gravitational waves. But, if they were more massive, who is to say that couldn't be the origin of the black holes LIGO is detecting? Although then it is a bit of a coincidence that they also have masses in almost exactly the range predicted by stellar evolution calculations...
A very recent paper by Wang & Zhao (2021) does suggest that the recent black-hole/neutron star candidate mergers could in be the mergers of primordial black holes and that the implied rate of these is still consistent with the upper limits to the possible densities of primordial black holes derived from microlensing experiments. The point is, there is nothing in the gravitational wave data itself that distinguishes primordial black holes from black holes formed after the big bang.
