[SilasX]

>Number of nodes is a poor metric that is easily gamified (pumped up), presenting an artificial picture. If a blockchain's economics purposefully incentivizes nodes, then number-of-nodes is entirely subsidized, in one common example.

I'm not sure that this dynamic would compromise the metric's usefulness. A cryptocurrency can only offer such incentives in-protocol if it's made the currency have real-world, persistent value. So any ability to bribe users to run nodes would itself be a validation of the cryptocurrency's success/influence/etc.

(That is, being paid 1000 ScamCoins a week to run a node won't be much of an incentive if they're only worth trillionths of a penny each.)

I do agree your next paragraph identifies a real problem though:

>Further, the "Sybil" factor - which one party controls many nodes - and other centralizing factors - e.g. 90% of nodes are on Big Cloud - also complicates the number-of-nodes use as a simple metric and useful comparator.

It's definitely hard to identify how truly independent the nodes are.

[cowtools]

Even if the nodes are independent, I don't think it really matters as much as the distribution of the hash-power. The non-mining nodes will not be able to resist a re-org by antagonistic miners.

[landemva]

Is this true for validating full nodes on a proof of work chain?

>> The non-mining nodes will not be able to resist a re-org by antagonistic miners.

A full node can pick whatever block it wants as the tip of the chain. Many nodes choosing the same would be a UASF. That would resist, by ignoring, the antagonistic miners.

[cowtools]

It does not matter because any new node joining would only need to connect to a single node that doesn't do the USAF in order to be converted against the USAF. The default behavior is to resist the USAF unless otherwise programmed.

Additionally, different nodes could receive different blocks at different times, meaning they will decide to do a USAF at different block heights.

The idea that non-mining/staking nodes do anything for decentralization or network security is basically cope for cryptocurrencies in which it is difficult for regular users to actually participate in mining/staking.

"The current system where every user is a network node is not the intended configuration for large scale. That would be like every Usenet user runs their own NNTP server. The design supports letting users just be users. The more burden it is to run a node, the fewer nodes there will be. Those few nodes will be big server farms. The rest will be client nodes that only do transactions and don't generate." -Satoshi

https://bitcointalk.org/index.php?topic=532.msg6306#msg6306

[landemva]

Full nodes validate the rules. They check and enforce that minded blocks follow the rules. This could be rules of a UASF which a group could take to ignore the antagonistic miner.