To understand why Bitcoin and other minable cryptocurrencies are DECENTRALIZED, you have to understand that no corporation,no entity, no government, nor any individual can control or own the blockchain or bitcoin.
Now let us start with the mining importance. To keep Bitcoin among others decentralized, you have to understand the basics. When you send Bitcoin, or Litecoin to another individual, what you are really doing is just passing them the keys to a safety deposit box. NO BITCOIN ever leaves the Blockchain. With that being said, there is no way for any entity to have control of Bitcoin, since it is not data on a drive.
All transactions are recorded on a pubic open source ledger, that would be the Blockchain. Now when you actually pass those keys to another person the amount you sent will register on the Blockchain as a transaction.
Here is where the miners come in to play. The transaction you sent will have 0 confirmations to start with, then as the blocks are solved and transactions are let out to the mining pool a transaction will be verified by a miner. Once the required number of miners have verified that transaction the amount will be shown on your digital wallet.
As stated the coins are never actually on your device, they remain always on the Blockchain. This means no Bitcoin, Litecoin, or anyother coin actually leaves the Blockchain.
Without the miners verifying the transactions there would be no decentralization, this is why the mining process, or proof-of-work- is the most important aspect of Bitcoin. Miners decide if the coin will even be worth mining. The miners decide if they will support any coin.
It is based solely on the proof of work, and if that coin is profitable to the miner, not any corporation. This is why decentralization can not be stopped. This is why many fall short of understanding.
MYTHS
Bitcoin is data on your computer-FALSE-
We already covered no Bitcoin leaves the Blockchain. What you are really doing is this; Let us say you are sending $200.00 worth of Bitcoin to your Relative. When you send it to his address what you are doing is sending private keys to your relative that shows that he is the owner of that particualr amount on the Blockchain.
Corporations or individuals own most of the Bitcoin -FALSE
If that were the case the hundreds of exchanges, and millions of faucets, and earning platforms all over the world would not be able to pay out, but they payout very regularly.
The Blockchain is the most impressive technology ever created. This is not just for monetary freedom, but it is a game changer in having an open source public record of all company transactions and smart contracts. With the Blockchain there can no longer be a closed loop if they use the original open source.
They say Bitcoin is known who has it, but have you ever looked at the Blockchain
https://www.blockchain.com/explorer

I see the following The address or hash, the time, and the amount of Bitcoin, and th value. I see it scrolling rapidly. There is no way to know if you are mining or sending. Anytime you use fiat or debit that will show. You had to use a third person.
Proof of work for a decentralized peer to peer system is the future.