When you are rapidly hiring, giving a candidate 2 weeks to complete a take home is a huge drag on the process. Instead, sandwiching 3 interviews (resume walk, leetcode, system design) into a 3 hour time period lets candidates move through the process faster.
hmm most of the take homes I ever got had a 1 week to complete but I guess I see it, I don't think I've ever been trying to get on a company that is hiring more than a small time at any time.