I know your question is really talking about the prognosis for the banks that CRHers currently use, but I think that's just one of the big factors that affect the viability of the hobby (and its continued future appeal to people like you and myself).
I think there will always be coin roll hunters, in some form, but they may start to increasingly find other sources of getting coins than ordering large amounts from local banks. The CRHers of the future may also become more interested in errors or oddities that continue to circulate as wild silver continues to naturally decline, as it has steadily since 1965.
CRHing for copper is a wildcard. I think many of the people who collect copper now will give up the waiting game and cash in their hoards before melting down cents and/or nickels is legalized.
I think we'll see fewer banks carrying large volumes of coins in the future. As long as businesses need coins, there will be banks to serve them, but I believe that need will be diminishing. When the business need for coin drops below a certain point (I have no idea what that point is, but I think we'll see it in the next 20 years), banks will carry much less coin and start charging more and higher fees to customize orders to a shrinking number of business and individual customers. As this continues to strengthen (it's already happening -- there are banks that will impose a fee for ordering your box of halves), I think you'll see CRHers start to pare off. I can't see many of these hobbyists paying $2-$5 a box that's likely a skunk.
In 2025 or 2030, if this board still exists, I think we'll still some diehard hobbyists who don't mind paying a fee to CRH (they're not doing it for practical financial gain, but more for love of coins and the thrill of the score) and a much higher percentage of people looking for errors and oddities. But I hope to be wrong.