Trigger is literally open source. That has nothing to do with how mature the node ecosystem is. If you want in-process queue systems you have a lots of other mature options. Trigger is a dedicated queue system, it runs in its own process and can be used from any language through its API. You seem to talk confidently about a topic I don’t think you understand.

Go has lots of mature in-process queue systems, yet River exists, because in lots of situation it makes perfect sense to have your job queue in its own process