I don't really think that's accurate. In my last interview cycle, I aced the livecoding portion at each interview and didn't practice any leetcode problems at all. In my normal workflow I write utility scripts in Python using only the standard library pretty regularly. If you know how to write complete, small programs using only the standard library of some language, you'll do fine on livecoding interviews. A lot of people struggle to do this because they only know how to work inside of a framework.