Those policies are worth the paper they're printed on.
I also note that if you're a USian, you've almost certainly been required to surrender your right to air grievances in court and submit to mandatory binding arbitration for any conflict resolution that one would have used the courts for.
I find this lack of trust quite baffling. Companies like money! They like having customers.
And, those who are pay attention notice that the fines and penalties for big companies that screw the little guys are often next-to-nothing when compared with that big company's revenue. In other words, these punishments are often "cost of doing business" expenses, rather than actual deterrents.
So, yeah. Add into all that a healthy dose of "How would anyone but the customers with the deepest pockets ever get enough money to prove such a contract violation in court?", and you end up a profound lack of trust.
This space is fiercely competitive. If OpenAI turn out to be training on private data in breach of contract, their customers can switch to Anthropic.