You can find a lot of historical examples, from people whose careers predated the publish-or-perish culture. A striking more recent example is Peter Higgs, who was awarded (among other honors) the 2013 Nobel prize in physics. Whether that makes him a "great" physicist is of course arguable, but he clearly did important work. However,
Peter Higgs, the British physicist who gave his name to the Higgs boson, believes no university would employ him in today's academic system because he would not be considered "productive" enough.
The emeritus professor at Edinburgh University, who says he has never sent an email, browsed the internet or even made a mobile phone call, published fewer than 10 papers after his groundbreaking work, which identified the mechanism by which subatomic material acquires mass, was published in 1964.
This article estimated his h-index to be about 9, but I've seen estimates of around 11 too. Either way, it's a very low number for the field by today's standards, for an established professor. To wit,
Speaking to the Guardian en route to Stockholm to receive the 2013 Nobel prize for science, Higgs, 84, said he would almost certainly have been sacked had he not been nominated for the Nobel in 1980.
Edinburgh University's authorities then took the view, he later learned, that he "might get a Nobel prize – and if he doesn't we can always get rid of him".