The traditional argument for increasing population is that if your population drops you end up with a much larger older population that needs to be supported by fewer working/productive younger people.
But AI and robotics are real. We already have self driving cars. Even the argument that leads to people not losing jobs requires some new, as yet not known, jobs to be found.
What’s extremely likely, however, is that, for the kind of work we do today, and the kinds of services and products we expect today, the need for humans to achieve them will reduce drastically.
So a smaller population is not likely to lead to worse outcomes. At worst it will lead to new services/products not being delivered.
And that’s all assuming new jobs materializing. If new jobs don’t materialize, what seems likely is a lot of turmoil and suffering as the world tries to figure out what to do with billions of unproductive young men and women, which have consistently been a source of terrible outcomes.
the "negative growth" through un-aliveing finnishes off the last tenious connection between reality and money, and all that will be left is hydraulic despotism/denial of service, will? be left, or IS left?