What's strange is that a lot of these centralized currencies are listed on coinmarketcap and are discussed on decentralized ledger forums. There is nothing in the future of centralized currencies.
That is incorrect. Decentralized and centralized currencies (BTW, XLM is decentralized - just because it is banking/fintech related doesn't mean anything) can belong in separate spheres without competition.
Privacy coins like XSPEC (probably x10 in 2018 at least - it is a sleeping giant), Monero, will have their own niches as well.
But without a doubt, centralized systems have a future.
This isn't me talking - it's the many banks and financial institutions which are adopting and looking at XRP, and in the near future XLM.
Buy XLM over XRP, BTW. XLM should be at least half value of XRP, so the price should easily x4 in the near future.