Please don’t get me wrong but cryptos are not fully decentralized. The backbone of all cryptocurrencies are miners. If there are no miners, there cannot be any transactions done.
I mentioned earlier that when 70 million worth of Ethereum was stolen last year, the ethereum community wanted to fix the bug and also reverse the transaction. In order to do that ethereum had to move to a new blockchain. The decision to move to a new blockchain was made by the miners and the votes that had the most weight were companies that had the best mining capacity. A few minority voters rightfully argued that if the transaction is reversed, then it removes the decentralized element of the platform. This can happen with bitcoin also.
Another big issue with bitcoin, is that the incentive for mining is going to keep reducing. Each time the mining reward is split the difficulty increases and miners get less bitcoin for the amount of power they use. Miners are also rewarded with transaction fees paid by the person who sends bitcoin. Now if all bitcoins get mined the only way miners are going to get rewarded is with the transaction fees. When that happens, I can see the transaction fees going up and up. If people don’t want to pay the transaction fees then there are going to be less miners which will make the transaction speed very slow.
Ethereum is trying to tackle the above issue by something called a proof-of-stake.
If it works out then Ethereum has a better chance of surviving in the long term.
Stallion Asset has explained the bitcoin bubble well: