Bitcoin will become the most decentralized cryptocurrency?
your question contradicts your post. you already say that bitcoin is the most decentralized cryptocurrency then at the same time ask if it will become one!!!
the fact is that bitcoin is the only decentralized cryptocurrency. others are either centralized or aren't currencies.
Every blockchain that emerged afterwards also started with a high degree of centralization. Although its creators intend to improve this as soon as possible,
that is intentional for most of them. for example stablecoins like Tether are completley centralized because that is their design the central authority has to issue the coins and they want to control the circulating supply. or shitcoins like XRP or ETH are centralized because they want to fully control what happens to their chain.