In my case, however, it was primarily about dancing with experienced but older dancers.
Aren't you mixing the difference between why you started dancing with how social AT develops?
We all had different reasons for starting. Historically, allegedly, to meet young women - and then the traditional life of marriage, home, kids and, if possible as an escape from work, recreational dancing. A few side issues related to gangs, knives, betting, drinking, etc. It doesn't work with the supermarket queue because there are other options away from the daily grind. Nowadays it's a social dance with certain quirks and a different demographic.
The question here is in different circumstances - paying the debt, 'paying forward', to encourage existing dancers and invite new ones. It's not particularly valid for beginners nor intermediates, nor 'hotshots', nor those who have no interest in social events, or others. At some point beginners progress to novices, to intermediates, to the 'advanced' space. That's a very large space where there are no accepted, verifiable, levels. They mature and gain wisdom

(ok, not all). Some have a philanthropic perspective and fall into promoting AT with milongas, even 'private' milongas, practicas, festivals, encuentros, TDJ, teacher, etc; others may see business opportunities there. Others just dance.
Yes, it's pleasant to dance with an 'advanced' dancer. What's not to like, unless they have an appalling personality? But, socially, it's also pleasant to dance with beginners, novices, and intermediates. But they're also dancing with someone who is considered 'advanced' (that may not be a high bar!)
High-end, elitest, formats die out unless they're fed. They age. They find other outlets. They discourage new recruits. They die.
But there's no magic, verified, validated, formula to build a tango community.
I don't see practical evidence to support it.
I've seen a few reports, primarily from the US, where teachers have encouraged a young social group with communal food afterwards, or other social activities. Probably comparable with evangelism.
My experience is that the high turnover period is mostly during the beginner hell period
It is for most activities - gym membership, language learning, keep-fit, etc. People need a reason to go out, pay money, and meet others. Being, effectively, humiliated by not being asked to dance, or abused for not understanding some rules, or lectured (mansplained?) on some 'sequence', etc, isn't encouraging. It's easier, and cheaper, to keep those already there than to recruit new people. But, in a metropolis with a supply of 'fresh meat', this is ignored.