The odds of a random reader (whether from Google SERPS or HN or similar) having a subscription are very low. I don't personally know anyone that has a subscription to the top 10 paid sites, and there's quite a few more than 10.
Google used to call the practice "cloaking", and would de-index you if you presented content to its crawler that didn't match what it provided to a visitor. https://developers.google.com/search/docs/advanced/guideline...