I wouldn't say it's delegated necessarily, but we consider a tech lead's goal to be unblocking the rest of the team, and if there's nothing specific to deal with at any point (hah!), dealing with these points is often the most obvious way of unblocking for the future.
Which isn't to say that the rest of the dev team can't do any of these things, but the tech lead is almost always the most experienced dev, and a lot of the DevOps type points aren't concrete ticket items, and a ticket which basically says "Explore [X] to see if it'll help" is (a) potentially too abstract for a very green dev and (b) the tech lead is probably best positioned to judge whether there'll be any meaningful help in practice.
By way of example, I might write a dev ticket along the lines of:
Background/Goal: With a larger userbase, we would like to add a moderator role. Users with this role would be able to hide posts, but not have any other elevated privileges.
Suggested Implementation:
* Add Moderator to the UserRole enum
* Split the post hide/deletion privilege into two separate privileges
* Associate the post hide privilege with Moderator and Admin roles
* Associate the post deletion privilege with only the Admin role
But a "improve the deploy process" ticket would probably look more like:
Background/Goal: Deploys currently take fifteen minutes on average, from start to finish. We would like to cut this down if feasible.
Potential Lines of Inquiry:
* Can we build things in parallel?
* Can we add more CPU/memory to our build environment?
* What would implementing blue/green deploys look like in terms of cost and benefit?
Comparing the two, you can see that the second is a lot more abstract--and maybe this is just me being bad at ticket writing!
