is it actually essential or is it overhyped?
I completed 250+ questions on Leetcode, following the Neetcode 150 list. I can say that my experience can probably pass any initial OA without much difficulty ATM. I have been doing Leetcode for about 1 year now, but I haven't been doing much since August of last year.
I have a spreadsheet of every question I've done in the past. In that spreadsheet, I track the day I completed the problem, the day I reviewed the problem (if I didn't get it on first try), the topic of the problem, and notes that will help me review the problem in the future.
Leetcoding is important. Of course, being able to talk through your progress is more important. Therefore, I suggest finding mentors who are willing to do mock interviews with you and doing them after you feel comfortable doing the basic questions. Leetcode also has mock assessments for the Premium users, and I really like doing a couple of them for fun when I have the time to. They are organized by company and stage (OA/Phone/On-site), which is beneficial if you have a dream company.
best, akkkkira