How deep the bench of legacy D&D players?

Troy Press published a piece "D&D Rules, According to Past Players" based on a survey they did - and I am fascinated by the 'mentioned in passing' implication of a huge amount of non-active D&D players in the USA - something like 1 in 6 USA folk have played D&D at some point, apparently. Does this make sense? We poked at this before in "Comparing TTRPG player surveys in US and Germany" where we looked at the previous surveys from the same outfit - - Researchscape 2022 Survey and 2019 Survey which also look at who among the general US population has played TTRPGs. Here they pulled in 1,253 US adults and found 16% - 204 people - had played D&D at some point. They mention "the data was weighted to the U.S. population by 9 demographic questions. The credibility interval for closed-end questions answered by all respondents is ±4 percentage points" so we could conservatively say 12% or 1-in-8 is more representative of general population. If you want to go wild, you could say 20%, 1-in-5…