Who needs human when you have AI :p
To a certain extent, yes, the training data is blindly being dumped in. There’s no way terabytes of training data is being manually reviewed for accuracy. If for no other reason, it doesn’t economically make sense to do so. It’s simply not feasible for humans to manually currate all of that data and even if they did, human error still exists.
Your disbelief doesn’t mean it’s not happening. The data sources that go into AIs are indeed curated selectively. Honestly, what do you think happens, a webcrawler is told to just “go nuts” and whatever random data it spits out gets fed right in? Trainers pick their sources carefully. They deduplicate it, they format it, they do a lot of work on it.
Perfection is not required. Human error is fine in manageable amounts.