An alarming portion of people in software industry can't code. Leetcode or otherwise. This was shocking for me when I started interviewing but it is what it is. Most people just can't code.

I don't like brainteasers and never propose anything remotely intimidating. After all, interview is a stressful affair as it is there is no need to make it any more so. But I'll never hire a person who can't write a few lines of code on demand either.