If you think about it, it's kind of weird for a product to have a single price. Everyone who would pay more is paying less.[1] It's much more profitable to just barely meet demand for every one while keeping the lower bound at the cost of production. You're right to point out that insurance operates with price discrimination. Student discounts and senior discounts are another common example. There are many others.[2] Tinder has market power in the sense that they sell access to a unique user base. Sure, their competitors offer access too, but none are identical, and that difference implies an amount of exclusivity.

1. Consumer surplus

2. https://www.economicshelp.org/blog/7042/economics/examples-o...