This is supremely naive, in my opinion.
Big companies not only lie, some of them do so routinely, including breaking the law. Look at the banking industry: Wells Fargo fraudulent / fake account scandal, JPMorgan Chase UST and precious metals future fraud. Standard Charter bank caught money laundering for Iran, twice. Deutsche Bank caught laundering for Russia, twice. UBS laundering and tax evasion. Credit Suisse caught laundering for Iran. And so on.
Really it comes down to what a company believes it can get away with, and what the consequences will be. If there are minimal consequences they'd be dumb not to try.
Oh I just remembered a funny one: remember when it came out that Uber employees were using "God view" to spy on ex-partners, etc? For years. Yeah I'm pretty sure the TOS didn't have a section "Our employees may, from time to time, spy on you at their discretion." Actually the opposite, Uber explicitly said they couldn't access ride information for its users.