Would that single person handle different topics such as: UI/UX, security, backups, distributed systems, data migrations, infrastructure, …?

Sure thing there are engineers out there that know some about all of the above (I personally do all of that on personal projects) but you still need specialists, otherwise it’s you alone with all the unknown unknowns that the llm may claim to solve, but you cannot verify

> I think perhaps the assumption that engineering managers should have any employees may be outdated.

to me, the latest models and harnesses turn all devs into an engineering manager with one direct report. Some devs naturally take up the role and great things happen, for others it's like trying to get a fish to ride a bicycle. This is how it was pre-genai too so i don't think there's a right or wrong answer, some will take off with the technology and some will struggle.

> I’m struggling to imagine a project that would require more than one talented engineer and a bucket of tokens anymore

Try air traffic control?