They seem pretty vulnerable to being obsolete if there is any sort of substantial change in the prescription drug market. And there seems to be quite a push to change the prescription drug market. Just look at how convoluted their revenue generation is, there are like 5 middle men.
This is true of basically any major healthcare play. On the (at this point extremely) off chance that we move to single payer, for instance, insurance companies face an existential crisis. On the off chance that we fix prescription drug price gouging and absurdly inconsistent pricing and all of these problems that GoodRx solves for patients simply by _cutting them in on the scam a bit_, then GoodRx faces an existential crisis.
The fact that there are 5 middle men is... more of a moat in this case? They've solved a complex, intractable problem profitably. Does this mean they're a 20-year company? Eh, not without some significant additional revenue streams or pivots into different areas, and to that point I agree with you about their vulnerability. But for the next 10 years? These are good margins building a business that only incrementally reduces the fucking over of the consumer.