Centralized doesn't always mean bad.
Do you mean in general or only when it comes to cryptocurrencies? I would disagree with you, whether it's about central banks or centralized cryptocurrencies.
Bitcoin has many flaws as well. But it is still enjoying the highest popularity just for being the pioneer of the cryptocurrency market. Bitcoin transactions are slow. it doesn't have smart contract functionality. The block size is small and that's why we are seeing the requirement of having Segwit and LN sorts of addons.
The biggest disadvantage of Bitcoin is that it is not adapted to the extent that it is understood by the majority of the population, whose level of financial literacy generally does not go beyond taking out a plastic card from a wallet and remembering a 4-digit PIN. The greatest popularity is based on trust, which is based on decentralization, which is something that no other cryptocurrency has.
Regarding the slowness of transactions, if you were a beginner I wouldn't be surprised by such a comment, but if 10 minutes on average is what you call slow, that's quite fast enough for me. Of course for all those who have no idea what fee and mempool are, transactions can be really slow, but that's not a problem that should be blamed on Bitcoin.
To be honest, no cryptocurrency is flawless. All big cryptos have their own strengths and weaknesses. Just because some cryptos are somewhat centralized, doesn't mean they are worthless. Keeping our minds open will only pave way for more innovation in crypto market and that's good in long run!
Do you think that new xx tokens/cryptocurrencies every day have a positive impact on the crypto market? Are you one of those waiting for a new king on the throne or do you think that the resourceful and enterprising 1% should get rich at the expense of the remaining 99%? These innovations, as you call them, are nothing but a bunch of nonsense and false promises.