> Functional testing is a must now that writing tests is also automated away by LLMs as you can get a better understanding if it does what it says on the box, but there will still be a lot of hidden gotchas if you're not even looking at the code.

Well, there you go. Letting AI write the tests is a mistake IMO. When I'm working with other people I write tests too and when I see their tests I know what they're missing out because I know the system and the existing tests. Sometimes I see the problem in their tests when I'm working on some of my own. If you absent yourself from that process then ....