What skills do you consider "gatekeepers"?
I.e.
"What skills do you need to be an intermediate?" etc.
I fondly remember years ago that (in terms of L-basing) unlocking a solid, un-spotted Ninja Star (Ninja Bat if we're being honest) and maybe a Four-Step or Catherine's Wheel etc were pretty much the gatekeeper skills between Beginner/Intermediate or Beginner/Improver. Now, they're considered pretty basic and I'd argue have been superseded by things like Clumsy Pickpocket and Ballerina (or Big Lemoi if we're being accurate) as the culture has changed and grown.
Even looking back further, I feel like I remember seeing in an old AYI Manual (I think) you had the "Level 3" versions of the Great Wall Flow and Flying Buddha Flow which would be considered (in many communities) a pretty beginnery flow these days.
This is obviously just as skills, teaching and knowledge have improved and many acroyogis/communities have drifted more away from flows/washing machines towards more acrobatic individual skills/short sequences (not all, thankfully!) but I'd be curious to find out what people see as the "differentiators" between different skill levels these days.
I'd argue that the diversity of skills has played a big role too. e.g. A standing H2H is now far more common, and even L-basing F2H/H2H skills and transitions are too. We have new "styles" like whips, lashes, more icarians, pole and climbing skills and so forth. 10 Years ago when there was a far smaller repetoire things were easier to define - now you can encounter people who can do advanced H2H/F2H (especially standing) but struggle with flows or basic pops/icarian. Also therapeutics, Belly Basing and even counter balances etc are far less common too.
I'd love to hear some other POVs.