Besides more objective concerns the Bitcoin legacy may have a psychological impact: Once a Newcoin has "arrived" - will people buy a Bitcent for 1000$ if they know that quite a few people own quite a few Bitcents they bought for a Dollar or less? I don't see Altcoins becoming worthwhile in the next few years, but as Bitcoin becomes more widely adopted and the price rises, as the concept of cryptocurrency becomes general knowledge, people will be more and more concerned about the infancy period of Bitcoin and eventually create a successor. My guess is it will happen within 5-10 years from now. This doesn't mean Bitcoin will become worthless, it won't. But it will neither fulfill the prophecies of becoming the one major worldwide cryptocurrency. All it takes is the well-coordinated and widely supported creation of Newcoin once the time is ripe.
(EDIT: Clarification on my implication of Bitcoin wealth distribution being "unfair": I do not think it's unfair at all. Early adopters played a vital role in establishing Bitcoin. They will be rewarded for thinking ahead an risking money in a revolutionary project. Above I'm referring to the fairness *perceived* by the general public in 2022 after a major increase in price.)
not underestimate the urge to cash out. The bitcoins will eventually be in the hands of the people who possess the wealth these days anyway...