Let me start off by telling a story. At the height of peak-altcoin, a guy I know released some garbage coin with the sole purpose of trying to make money in a pump and dump. I told him, hey, why are you making this stupid scamcoin? His response was, "just what exactly are we trying to do here?" (i.e. being involved in cryptocurrency in the first place).
Before you try to create or engineer something, you first have to actually identify the problem you're trying to solve. The problem to solve is not decentralization, it's creating an alternative to rent seeking usury, aka slavery.
The current state of cryptocurrency consists of closed entropy systems like Peercoin, which are internalized proof of stake, and open entropy Bitcoin PoW systems, which are just externalized proof of stake in practice, not decentralized. Both are stake based and stake based systems have the following attributes, they're designed around someone monopolizing a variable then practicing rent seeking usury on everyone else.
The internalized stake is basically world domination on cruise control and should be shunned by anyone who doesn't want to be a slave, while the open entropy system of Bitcoin tends to give you the same result when you're just externalizing your metaphorical stake into the Pareto principle of the real world. This means cryptocurrency solves really nothing in it's current state, and things like physical silver coins as a currency would be vastly superior in terms of both decentralization and avoidance of usury or seigniorage fee.
Having said that, if you were to try and improve on cryptocurrency in some way, you would be required to remove the stake variable entirely. A system where you can't gain capital by leveraging assets on cruise control with no human intervention or attendance required. The only way to do that off the top of my head is either unprofitable PoW (which seems like it wouldn't work in practice) or by having all senders of transactions solve some type of decentralized captcha or other proof of work that cannot be put on cruise control for profit.
What you say here might hold water if there was only one cryptocoin. The fact is there are hundreds and there will be thousands upon thousands of them in the coming years. Decentralization comes from every one having an easy way to create their own money/token and embed usefulness in it, to work to make it valuable. Some will succeed in this endeavor, most will fail, it doesn't matter.
Decentralization is in breaking monopoly of state on creation of money and having everyone and their mother create some sort of loyalty points with value that others are willing to work for. This will be the end of state monopoly on money, this is what decentralization is about. Silver coins are awesome, no argument about that
