I was reminded today of a quote from Sunny King on the challenges Bitcoin will face. This is from an interview a few years ago:
Someone might think Bitcoin will continue to dominate forever but it is hard. Bitcoin was not gold after all, it was the first cryptocurrency but in the technology world, the challenge for domination can be daunting. Besides, Bitcoin has some risk factors with its design coming up probably within the next 10 to 20 years, when the generation of new Bitcoins reduces to a minimum. We shall see whether Bitcoin can sustain a good enough mining market by collecting transaction fees. Now even if it manages that, there are still concerns that 51% of attacks might eventually get to Bitcoin. Remember this year we see it can get to a top 20 project. If this type of event happens to Bitcoin eventually, of course, it would not bode well for its long-term dominance.
Link: https://medium.com/vsystems/the-anonymous-fireside-chat-with-sunny-king-at-the-capital-c19563cbcfd5