There is no perfect answer to these questions, unfortunately. However, it’s very important to acknowledge that the existence of cryptocurrencies inside public blockchains is pretty much justified.
Think of it like this. Why would anybody put their computer resources to support a public blockchain if it’s just for the ‘common good’ and nothing else? It’s normal to expect most people want something back in exchange for their support to the blockchain network.
This is where the incentivization matters. By having a native cryptocurrency inside your public blockchain system, it incentivizes the outside participants to provide their resource to help you secure the network. They support your network, they get your crypto when they successfully verify a transaction, and your system grows and becomes more decentralized.
The thing is, it’s less realistic to expect a better level of decentralization when you don’t provide incentives. And that’s the problem with a blockchain system. You always want to have a fair level of decentralization. Check Wikipedia explanation on Bitcoin economics
, it might help you to understand things better.
The bigger issue comes down to the crypto economics itself. How much is considered enough and fair incentive? How much do you need to spend to lure validators or miners to support your blockchain? What would be the consensus mechanism? and so on.
While every blockchain has different answers to these questions, at least they all can agree that giving incentives to network validators or miners is extremely important to keep a fair level of decentralization. To understand why decentralization matters, you should read our centralized network vs. decentralized