To believe that nothing will ever be good enough to replace BTC is outright stupid. You cannot just merge all new and/or useful tech into an existing "product" forever and "block" all competition by doing so.
That's what nearly every bitcoiner believes. It is laughable. When they try to compare bitcoin to the early Internet what they want is an Internet that will only ever have one website.
They are currently flirting with the idea of increasing maximum block sizes from 1 megabyte to 20 megabyte so the transactions per second will increase. What they don't tell you is that even if they hardfork bitcoin so the new block limit is 20 megabytes the transactions per second will be the same as what Litecoin can manage now. In other words, bitcoin needs a major hardfork just to have the same transactional capabilities of litecoin.
Bitcoin is a PROTOTYPE. All it has is a three year head start which has given it a massive network effect. It has a reclusive, anonymous creator who holds 5% of all bitcoins that will ever be mined. If just one of Satoshi's coins started moving the entire bitcoin community would collectively shit their pants.
I have always said that if Bitcoin was created tomorrow it would be derided as a heavily premined, incredibly slow shitcoin. But it is bitcoin.