I really hope nobody had themselves convinced that software engineering couldn't be automated. Not with the code enterprise has been writing for decades now (lots and lots and lots of rules for gluing state to state, which are extremely structured but always just shy of being so structured that they were amenable to traditional finite-rule-based automation).
The goal of the industry has always been self-replacement. If you can't automate at least part of what you're working on you can't grow.
... unfortunately, as with many things, this meshes badly with capitalism when the question of "how do you justify your existence to society" comes up. Hypothetically, automating software engineering could lead to the largest open-source explosion in the history of the practice by freeing up software engineers to do something else instead of toil in the database mines... But in practice, we'll probably have to get barista jobs to make ends meet instead.
The experiences people are having when working with big, complex codebases don’t line up with your gloomy outlook. LLMs just fall apart beyond a certain project size, and then the tech debt must be paid.
Is it gloomy? I personally liken it to inventing the washing machine instead of doing laundry by hand, beating it against a washboard, for another hundred years.
If you want to know what will happen to software engineers in the US just follow the path of US factory workers in the 90s.