Miners have one job.
all miners do is cement an ordering of transactions.
what is controlled by the plebs running full nodes?
Your full node protects you. It does not protect the network.
what is controlled by people using custodial wallets?
  • They have the control to Tweet about how screwed they are that they do not have access to their funds (for the latest example, ... see Poolin miners, where poolin was the custodian for their mined earnings that they had not yet withdrawn).
  • These custodial wallet users may (or may not, depending on the jurisdiction) have the ability to petition the courts for relief if the custodian does not provide access to the funds, or if things are worse, these custodial wallet users may be able to submit a claim to the trustee for the custodian's bankruptcy case.