I would not say a centralized system is much better than decentralized system. I believe both of them have its own advantages and disadvantages. The real problem lies not on the currency and the system but rather on the people who are using and operating such systems. Humans are greedy and it is the main source of problem and whatever system we may choose as long as human nature does not change for good then both centralized and decentralized system will encounter problems on the way.
Yes sir! While there's no perfect system in this world, we as humans are responsible for making good use of our money whenever it is. Sometimes, because of greed, we tend to ruin the whole purpose of a system, making it centralized in the long run. Ripple is a good example of this, since it started with good beginnings, but now it is extremely centralized by its own company. It's just like the internet where it started as a decentralized system, but then it turned out to become centralized due to corporate interests from big companies such as Google, Facebook, and Amazon.
While Bitcoin is still decentralized, there could exist a high possibility to become centralized in the future, because of human greed. We've seen many times how the Chinese sector has most control over Bitcoin's mining hashrate, which is only a result of greed as they develop new miners that defeat the purpose of ASIC resistance (like it has been done with ZEC, ETH, and more). As such, if Bitcoin continues to be dominated by China, then it'll present a huge risk towards its longevity, since it can be disrupted at will. Some say that 100% decentralization is practically impossible and a myth, since there is always a certain level of centralization in any system. Bitcoin operates the same way, where mining pools have centralized the mining process, making the cryptocurrency a semi-decentralized one, rather than a fully decentralized one.
All in all, I wish that Bitcoin would remain as decentralized as possible, as I think that it'll lead it towards future success. The reason why it's still demanded and used by anyone around the world, it's because of its decentralization. And if that is taken away from the original cryptocurrency, then the whole ecosystem would be doomed.