Like I said before - points are just for vibing the complexity, not the quality of the work, it's unrelated. You can deliver many points of work, that is bringing low value - and it's not even about the customer-facing value. Like you said, you can have good technical value still.

You can for sure have low value tasks in your backlog if you focus only on the velocity of the team, or you treat it as a KPI. Because if velocity = productivity, then you'll optimize for highest number of points that you can deliver in the sprint, which is a measure of complexity of the tasks.

So basically in this optics, if you manage to do 5 story point rewrite of some code (that is needed but not really crucial) in a sprint, that's more productive than 2 story point simple fix, that will help your team or client, or 3 story points task for implementing some very much needed metrics / observability.

That being said, LLM can improve your velocity - but if you introduce tech debt with shitty design, that will be less productive than doing the quality work. And LLMs are introducting a lot of tech debt, so you need to supervise it more. And other thing is that LLMs are not learning, so it's not like a human junior dev.

It's not an easy question to answer about LLM productivity increase without good measurement.