I think when an action affects multiple nouns at the same time, it starts to look more like a verb oriented approach. For example, say you have some kind of fundraising event donation system where you can have a donor donate to people or teams of people participating at the event as well as the event itself or the organization as a whole. So, something like a 5k run to save the whales.
When you create a donation that impacts potentially an auth record and a user account (if they create one), a donation, as well a it could end up touching the event, participant, team, or organization itself. Now, do you make all those data changes as a series of nouns with actions that you must do in some particular workflow and order? Or, do you have a higher level verb that you throw input at and it returns a result, doing whatever it needs to do in the process? Or do you have a noun with a single verb that starts to feel a lot like RPC?
In some ways they are equivalent, you have input, state change, and output. In other ways they are different. I would expect in REST you might have to hit multiple nouns to change all the state appropriately and I'm not sure there is a good mechanism to enforce that it happens correctly according to the desired workflow.
In the end, for things beyond CRUD and reporting, I think complex actions that touch multiple verbs is often better represented as a verb. However, I would love to see concrete examples of how you model complex workflow based state changes as a "transaction" or workflow in REST or if REST api's inherently opt out of such behavior.