Thats how a lot of application layer startups are going to make money. There is a bunch of high quality usage data. Either you monetize it yourself (cursor), get acquired (windsurf) or provide that data to others at a fee (lmsys, mercor). This is inevitable and a market for this is just going to increaase. If you want to prevent this as an org, there arent many ways out. Either use open source models you can deploy, or deal directly with model providers where you can sign specific contracts.
And you are getting something valuable in return. It's probably a good trade for many, especially when they are doing something like summarizing a public article.
I'm not so sure. I have agents that do categorization work. Take a title, drill through a browse tree to find the most applicable leaf category. Lots of other classification tasks that are not particularly sensitive and it's hard to imagine them being very good for training. Also transformations of anonymized numerical data, parsing, etc.