When you pay for something, you stop being the product and become the customer instead. That's a big deal.
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.
It used to be the case in the past, perhaps, but not now.
Now you just get fscked twice.
Not really, not for 1¢/day. Most massive platforms that I use for free (Google Workspace, Cloudflare Pages, even Oracle Cloud always free tier) have outlived many low cost solutions I tried.
I've never understood this mentality. Why can't they still sell your data after you pay them? Porque no los dos?