When you say "valuable," valuable to what/whom? All nodes validate & relay transactions, so how does the network know (and why should it care) about how much BTC the node's creator has? A node is a node, it validates according to its ruleset, no more no less?
How does the network know how to value a node? I must be missing something very basic.
When there are human beings on the other end of the nodes , those human beings have agency to value one node over another. They can value a full node or a SPV node differently because one offers better security and the other requires less resources(Fraud proofs and pruned full nodes will offer a greater variety.) Nodes that are controlled by merchants/exchanges ect have more value because the users and businesses value them.
The Code doesn't have any AI in it that makes a conscious assessment as to its relative value. The humans at the other end of the nodes are merely an extension of the network that place value on the nodes and the rules behind the code.
What you are missing is that Humans are part of the Bitcoin network.
We're discussing the impact of nodes on Bitcoin network, not value of full nodes vs. SPV wallets
to you.
The "humans at the other end of the nodes" are irrelevant to this topic, beyond their choice of which node to run.
They have nothing to do with securing Bitcoin.
This is getting too silly.