To add some thought to this.

The interview results need to be reasonably repeatable and comparable to assess interviewer skew and bias.

The result is that the interviews themselves inevitably end up being somewhat predicable. And what is predicable you can prepare for, giving you predictably better results.

If you are top 0.1%, sure you will nail them without much prep, but most of the candidates would spend some time preparing.

You mentioned that it is not about Competitive Programming/leetcode stuff but a daily real world work. So how do you prepare? Just continue doing your daily work?

You prepare by making sure all your bases are covered. In my daily work discussions, for example, I tend to be very hand-wavy about concurrency, calling everything “locks” and hoping people understand that I can dig down into the details when needed. When I’m interviewing I don’t want to just hope, so I review my concurrency primitives to try and make sure I won’t put my foot in my mouth.