Validators are businesses run on top of digital nations. They provide any type of services, from security to marketing for those digital nations. Citizens of those nations can choose to grant any of those businesses with money, just like a vc, and receive a reward for it. Unlike in the vc world, they can monetarily decide to stop its funding if the business doesn’t benefit the nation.
Hence, role of a validator is:
to benefit the digital nation and its citizens if its getting funded by its citizens