Athleticism is not something I see at any milongas.
My response depends on the answer to "What is athleticism?" That might be "balance," "endurance," "flexibility," "precision," "reflexes," "speed," "strength," etc., depending on what kind of athlete you have in mind. I do see balance (retaining axis), endurance (dancing all night), flexibility (dissociation), precision (in footwork), and reflexes (responding to sudden developments on the floor). I don't see very much speed or strength except on the part of people who rush too much and muscle through movements, which is mainly a leader-side flaw.
I don’t see ladies in 60s who are good dancers have any problems getting dances. Where I do see ladies in 40s and 50s losing out to younger crowd is when their skill level is below average ar the milonga. Problem is no one tells them.
Unfortunately true. Our community here is still overwhelmingly man = leader and woman = follower, so I'll be a traditionalist in this remark and later:
A lot of women who start tango here decide to stop lessons because they're getting invitations for being pretty and young, and are being "taught" on the floor. Then they age out of that zone and get dropped by people who used to invite them, in favor of incoming youngsters. By their 40s, many start complaining about it, and most quit tango by their 50s. Just about anyone dancing in their 60s continued (or resumed) lessons, and so is a competent dancer with no shortage of invitations from partners who value skill above youthful looks.
That doesn’t mean I haven’t heard from older men who avoid certain milongas because they don’t get enough dances. I blame them.
Yep. They're the guys on the inviting end in the above remark. Eventually they age past the point where anyone young wants to be their protégée or darling, and have to win tandas on the strength of their skill alone . . . which of course is absent because it atrophied due to dancing with women who quit lessons instead of with ones who kept training and became good. Your skill finds its level largely on the strength of your partners' skill.
They are friends who have been dancing for 20 years but are short on techniques and other basics that should have been fixed a long ago.
Both leaders and followers tend to assume "dancing for a long time" means "good at dancing." That's utter garbage. At best, it means "good at faking it" or "knows how to work the community." However, the acid test is whether advanced people who kept up
their work choose to dance with these people without knowing who they are.
While age definitely plays a role, the skill level and gender imbalance/balance dynamics play far greater roles.
Around here that's true. Followers who sit just about always sit because either they're outnumbered and the math works against them, or they've ditched lessons and aren't very good. I've seen almost no cases where, given balanced roles at an event, a skilled dancer didn't dance.