Helix MWR went invite-only, I believe, around 2022.

The owner will personally send invites to people - and yes - it's usually CEO's, managing partners, and business-owners who are targeted (although - I believe they also look for people who they think will be "rising" into major executive positions as well). There was a time where a good amount of invites went out (this was shortly after they went invite-only) - but it's gotten really difficult to receive an invite now.