So some companies will bend over backwards to avoid sharing pay info. But how well does this work when employees can and frequently will report salaries on thei

So some companies will bend over backwards to avoid sharing pay info. But how well does this work when employees can and frequently will report salaries on their own to e.g. glassdoor, levels.fyi etc? It seems like this information is in broad terms already out of their control, and making actual salary bands for new hires in each role would be clearer than the murky stats from employees who report their comp on their own.