In reality, not all people who use cryptocurrencies consider decentralization to be something essential and of primary importance. Many of them don't care how decentralized the network is as long as their transactions are processed faster than on the Bitcoin network and their funds have never been frozen or seized. I have met more than one person who said that they use centralized networks and do not see any problem with that. There is no point in trying to convince them otherwise, because each of us finds what we like in cryptocurrencies.
I even believe that 90-95% of crypto investors today don't care about decentralization or privacy as much as they claim. All they care about is profit, cheap transaction fees, nothing more, and they are just trying to deny that.
If people really care about decentralization, privacy, they won't use centralized exchanges and invest in altcoins. But look, the trading volume on CEX is many times larger than DEX, which shows that decentralization has never been our top priority.
I bet even if bitcoin loses its decentralization but it still increases in price and makes huge profits, people will still be happy with that. They will only really leave if bitcoin is no longer profitable.