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.