These companies filter employment based on leetcode ability and they also promote a workplace where you move up or out within 4 years. To tell employees to ignore leetcode means they are stuck at there current faang where getting promoted internally is much more difficult.
This service is really for current faang employees who need career advice because developers outside this bubble are dealing with other challenges.
I would make this a premium service and charge 1,000 per year because your target market is niche, uniquely rich and small. Developers outside of these bubbles are dealing with host of unique issue like startup problems, or government employees issues or issues working with large banks or freelancing. Developers want to know how to switch stacks after 10, 20 years while keeping same pay. Developers want to know how to create a part-time startup while working fulltime. These issue don't apply to your service.