In a non-jokey answer, Kiwi Farms is basically just a group very much about documenting and archiving various interesting and embarassing things about people that have been posted on the internet. Though there are various successful, and mayhaps powerful (whether politically, or monetarilly) people on Kiwi-Farms, the website is largely predicated on anonymity of its users, hence if a particularly powerful forum member did something- it is unlikely they would say it was them, and hence, it is unlikely that we (or anyone else) would know Kiwi Farms is behind it.
Despite the various news outlets' claims, Kiwi Farms hasn't really driven anyone to suicide, and though it may be argued we've cost a good few lolcow their jobs due to the information hosted on this forum- I would chalk that more to the proactivity of the business owners, and the self-destroying stupidity of the lolcow for posting things that could get them fired online.
If there was any notable display of 'power' Kiwi-Farms has, it is in the know-how and sleuthing skills of many of the forum posters on this website; As well as notable writing prowess from certain individuals in being able to make entertaining and informative OPs and breakdowns of various happenings.
That said, Kiwi Farms is one of the few websites that have withstood as much kickback and efforts to be removed by private citizens/netizens, and yet still remain on the clearnet. While I wouldn't note that as 'the forums being powerful', it does stand as a testament of the farm's resolve that "we" (or more specifically the persistance and know-how of our Dear Sneeder Joshua "Null" Moon) have persisted, when other forums with only a fraction of the kickback have splintered or gone down.
.