Take a look at the list of validators here: https://xrpcharts.ripple.com/#/validators. First of all there are many their own validators with ripple.com label. Second thing is UNL, press (?) near it at the top of the table. What the heck is that - Included in the recommended UNL? Why the heck anybody is allowed to include or exclude me from recommended UNL? The third thing is incentives to be a validator. There are no profit based incentives, no profit from being a validator. There is no sense to be a validator, because the requirements are too high. It's just ugly based centralized system.