And reason they can get recurring revenue for what is indeed basically a linter, is that what it lints your configuration files against is not just best practices but also regulatory compliance. And that gets hairy enough and changes often enough that it's usually worth it to pay for it to be someone else's headache.
The real value is it's linter for _any_ cloud config - you can use terraform or cloudformation or just click around in user interface, and Wiz's rules would still work.