mining must also go through a market evolution, it must stop growing as some point. locking in to PoW MM for ever is not evolution it is manipulation, who knows the bitcoin killer may use proof of Bandwidth or proof of Block Archiving. if you do that with a SC I think Bitcoin would become obsolete as the value will leak into the SC as fast as rewards diminish.
so essentially your concern is now that Bitcoin gets replaced because a better technology came along
its not better technology that will replace bitcoin its better propaganda and consumer confidence keepers, some improvment i can see implemented in SC adjusting the fixed supply to a constant 3% economic growth stimulates (because economists think moderate monetary growth is good) increasing the tx fees, we need more miners for security, and teh proponents saying you the people, listen up, we have embraced bitcoin's blockchain technology its been improved and is safe for consumer adoption, were moving our national currency into the blockchain.
and in the blink of an eye Bitcoins tiny billion dollar market cap is absorbed and assimilated and usurped. Replaced not by better tech but by confidence spinning.