Bitcoin is getting near to a 51% control in network hashrate by a single mining entity called Bitmain. This is very bad, because if Bitmain's monopoly over ASIC hardware expands, then it would have complete control over the Bitcoin network. At any moment, China could force Bitmain to shut down all its mining operations, severely affecting Bitcoin's security and long-term sustainability. On the other hand, China could force Bitmain to perform a 51% attack on the Bitcoin network to disrupt it and turn it into a useless chain.

As such, any possibility could exist for Bitcoin to become centralized because of its current PoW algorithm. If Bitcoin were like other decentralized coins in the market today, which have implemented ASIC-resistant algorithms, then it wouldn't have the risk of a 51% attack since the hashrate would be spread out by people around the world with access to CPUs or GPUs. However, the way Bitcoin is leading to, is towards centralization unfortunately, as big mining pools (mainly operated by Bitmain) have the most dominance on the Bitcoin network.

Therefore, what once started as a decentralized cryptocurrency, could turn out to become centralized in the future if the developers and the community don't do something about it. This is like the internet where it once started as a decentralized system, but now it's highly centralized controlled by big corporations like Google, Microsoft, and Facebook. Just my thoughts