This is literally the only way I've gotten job offers. I'm a very competent programmer, but when I'm asked to solve some silly puzzle with someone staring over my shoulder, I freeze under pressure and can not think at all. Luckily not everyone thinks solving leetcode problems is a good way to hire.
If you can't code under pressure, you aren't a very competent programmer. Real world projects come with high pressure scenarios for software engineers. Code monkeys may be able to get away with low pressure, minimally impactful projects.
Code now or die isn't usually something most people face in their day job.