I think it's a multifactorial cause and the first stuff that comes into mind why:
- Everybody or almost everybody is doing it and it's an advantage. Don't do it and you are missing out of or giving yourself a disadvantage.
- More workload by the educational system. The previous generation had less demands and less concepts to study. We got new facts popping up in all fields and these turn into trivia that most won't get to be able to use in daily life but somehow framed like it matters a lot. Looking back at my math teacher who insisted quadratic equations was big deal.
- They grew up in a culture where it's a norm and are less punished for it. You don't use AI, you get the outcome of #1.
But yes, oral exams will be a must if you want your professional services hired to know what they're doing.