However, not paying does not mean that you necessarily become "the product".

Offering loss-leading products is a common business strategy and I'm perfectly okay taking advantage of this for hosting needs that fit a vendor's free tier.

Static hosting is very cheap to offer and gathering free tier users will gain developer mind-share, which helps the vendor can sell their truly money-making products. To pick a clear-cut example: AWS Lambda does not collect any additional data on free tier usage compared to paid usage.