I worked at a Silicon Valley company that's extremely famous and spends millions on PR to promote their reputation. I was verbally promised a certain starting salary and moved from the East Coast to take the job.
After I started, my paycheck was for 15% below the promised salary. My boss kept assuring me that it was a mistake that would be correct “at my next performance review.” Since I'd moved 3,000 miles, shipped all my stuff, broken up with my s.o., and let go of my prior apartment, I was highly motivated to believe him. Idiot me.
They managed to have reasonable excuses for why it couldn't happen for 18 months. At that point, I asked for the raise to be retroactive when my boss brought it up again. He said “paying you that much at this point would require the Board of Directors to sign off on, because it's such a large variance.” So I turned it my notice.
I later found out that (a) they had to hire 2 people to replace me — but even though the total expense was higher, since each one was inside the same salary band I'd been in, it didn't require board approval, and (b) a friend of mine who was privvy to the HR meetings said they had never intended to fix my salary. They genuinely didn't believe I'd quit and that they could just keep stringing me along.
That was when I learned that positive press about company culture is bullshit, people are not paid what they're worth–especially not high performers, and promises from a company are worth absolutely nothing.
None of my experiences since then have contradicted any of those learnings.