"If it's free, you're the product" bugs me every time I see it. It's totally not true.
It's very easy to come up with counter-examples. Mastodon is free. I'm not the product. Linux is free, gcc is free, Firefox is free, F-Droid is free, ad nauseum. Counter-examples the other way, too. Windows 10 is quite expensive, but I'm still the product. Ditto smart TVs, smart phones, smart anything.
I don't think there's much correlation between "free of cost" and "I'm the product" to speak of.
"If it's consumer-targeted proprietary tech, you're the product, regardless of whether you paid for it or not" sounds more accurate to me.