By SDET I mean one who reviews not writes code, maybe we have different definitions of that term because you also mention humans being needed to guide the processes.

Even still, other professions interact with the real social world which is not necessarily the case with programming. A lawyer will always be needed because judgments are and must be made by humans only. Software on the other hand can be built and tested in its own loop, especially now with human readable specifications. For example, I wanted to build an app and told Claude and it planned out the features, which I reviewed and accepted, then it built, wrote tests, used MCPs including the browser for interacting with the UI and taking screenshots of it, finding any bugs and regressions, and so on until an hour later it came back with the full app. Such a loop is not possible in other professions.