I don’t know what you think is magically different about an infra person who can apparently maintain arbitrary numbers of services and is somehow immune to the same boredom you fall under.

And look, infra people are harder to come by and more expensive than devs so no company wants to waste our time bumping dependencies and fixing non-infra related bugs. If you’re big enough to have a team or teams of maintainers then they would go there. If not then it’s ship it maintain it.