At some of my past jobs and the current one, this kind of algorithmic knowledge was important to build features that were differentiators in the market. As much as people love to pretend, not every single possible solution is in a library. Sometimes you're the one building the library.
It doesn't have to be leetcode, but candidates should at least be able to produce some code that doesn't come from the README of their favourite framework.
Also, talking for 30/45 mins can be enough, but it produces false positives when you have people coaching candidates. I've had people completely acing interviews that it felt like the perfect candidate. Well, it was rehearsed. When I asked for a fizz-buzz type question they completely messed it up.