I commonly use it for dielectric test or test rated maximum working voltage, to part's failure.
A big problem today is counterfeit or substandard parts, or parts that are quite old. While the parts we get from the proper supply chains [ e.g. Digikey] can unlikely be counterfeit, for my personal use I get surplus or whatever from eBay or worse. A simple way to test its not likely counterfeit is if it lives up to its spec sheet, or a test that hinges on quality materials and manufacture, the dielectric withstand test.
If not a PD supply, you can get a Hi Pot or Insulation tester on eBay for about the same price, best capable of up to 3-5kV.
Industrial HiPot testers tend to be heavily ab/used in life and when sold on eBay, and may not have much life left.
$<200 new insulation testers from China are a good low cost substitute but they are commonly not continuously variable.
In general, brand name lab supplies of any type OTAH tend to be taken care off so they are better buys.