Having a sump pit and pump does not automatically mean water in the basement. In many homes there were water problems in the distant past and systems were put in to alleviate the problems (french drains, fixing gutters and landscaping on the outside to route water away from the house, fixing cracks, etc) and the homes haven't leaked for years, but the pits and pumps are still there. In 93 with the big floods that we had (500 year floods), homes leaked that hadn't leaked in the past, but levies were also changed which changed the water flow and people haven't had issues since in some areas because of changes that the municipalities did, with out the need to put in sump pits, but some went on and did so anyway as insurance against a future flood of that type.
After the 93 floods, many builders put in sump pits just "because". It became an expected norm and in many cases was required by local zoning codes. At the same time homeowners put in pits if they were finishing off or renovating basements, if they had ever had any issues, again due to zoning codes and as an insurance policy based on the 93 floods.
This year we had a "different" type of flooding - in 93 it was torrential rains and water from up north that flooded us, this year it was continuous rain that soaked the ground so there was no where for more water to go and the rains kept coming so if anything was going to leak it did. Homes that had NEVER leaked before, leaked this year as the water had no where to go except into the homes, so again people are putting in pits to protect against future issues
All of those can be reasons why someone has a pit and pump, even if they don't have a water problem. As Bob noted, the seller's disclosure on this house indicates that it does not have a water issue in the basement. If a home has good storm drains around it and they are kept clear of branches and trash that's where the water from the "higher ground" should be going. All homes should have a swale around them to keep the water away. The swales over the years get filled and need to be dug out again and many home owners neglect to do that, but it's an easy fix when it happens.