Running a node (or multiple) is how you verify that the Bitcoin you are interacting with is legit (according to the rules enforced by your node). Making multiple nodes does not magically force others to use your nodes to verify their own txns.

So if someone wants 50k nodes that enforce the wrong rules, they're free to create that fork and start using it themselves. Any "non consensus coins" they try to spend will be rejected by every node that is enforcing the "correct" rules.

Should we focus on getting more plebs to run a node? A pleb should run a node for their own benefit. How else can they be sure the sats they "own" are actually theirs? We should educate users of this fact for their own protection.

Do more plebs running nodes "help the network". Yes, it helps with decentralization but its not as simple as "more nodes the better". I.e. one node per pleb is fine. If every pleb ran 10 nodes instead, it wouldn't be any better than 1 node per pleb.

If you run a node, but never use it for anything, that node is almost useless. It can still help relay blocks, but in terms of its significance towards "validation and enforcement" its basically useless. Even if you run 10k nodes and never use them, its not very helpful for anyone.

There is a concept of "economic nodes". These are the nodes that back public block explorers, exchanges, wallets, and services that handle lots of BTC or are used by lots of people to "verify" lots of BTC.

These large economic nodes are the most important ones. Suppose the most popular block explorers and exchanges started using a forked node and stopped supporting BTC. This would cause a great disturbance as many people who use those economic nodes have trusted them with verifying "what is bitcoin". And when they say, "this fork is bitcoin" they are likely to fool lots of people.

Notice that the economic nodes don't need to run thousands of nodes to be successful in pushing the fork onto users. They just need to first gain the trust of thousands of users and prey on the fact that many of those users are not verifying separately with their own nodes.

An attacker with thousands of nodes could pull off an eclipse attack, whereby the attacker's nodes manage to become the only peers of a node. Thus, they can withhold relaying blocks to this peer and make them fall behind. Its really difficult to do since it only takes one honest peer to keep the chain updated.