Mate there's no need to arc up and call me ignorant or a bullshitter.
If the shoe fits...
As far as I'm concerned you're no different than the AFL fans from Canberra on Big Footy and other AFL platforms whom will tell anyone that'll listen that they don't personally know a single RL fan, that RL's popularity in Canberra is overstated, that Canberra was an "AFL town" before the Raiders and that Canberra's just waiting for it's own AFL side to become one again, etc, etc.
It's all just BS pushed by the delusional or dishonest, and I'm over it. Canberra is neither an NRL or AFL town in the way that Sydney and Melbourne are NRL and AFL towns respectively, there's nothing wrong with that, and the people whom are trying to change it tend to be arseholes whom whitewash history to fit their agenda.
You made a claim that's counter to my 32yrs growing up in Canberra and I simply asked you to give me a source proving it. My experience may be anecdotal but it's not really trumped by vague references to google and social media.
AFL participation numbers have proven to be a poor measure of popularity as well. They're quite often found to be false or don't translate to overall popularity. See AFL participation numbers in NSW and QLD vs TV ratings.
If you do any research you'll quickly find that all numbers that could be indicators for the popularity of each sport in the ACT are shaky at best, and even experts in the field freely admit that the region's sport preferences and culture is severely under researched. In other words, you're asking me for numbers that the codes probably have but aren't publicly available, and all we have that is publicly available are highly debatable as to what they actually show.
Participation goes the AFL's way handily, but that's not really surprising considering the physical demands of RL compared to Aussie Rules. It also doesn't include touch and tag when you really should if you want an accurate reflection of RL participation in Canberra, but the problem with touch and tag is that there's no way to differentiate between touch and tag players that are using it as a non-contact form of RL and those that are playing them with no significant interest in RL.
Ratings go the NRL's way, but you'd expect that with Canberra having a local team in the NRL, where as the AFL's fanbase in the ACT is split between all the clubs. That also doesn't include streaming, and ratings collection in the region is basically a glorified guesstimate anyway.
Attendance is hard to compare as there's no like for like comparison. But considering the numbers GWS pulls it's not unreasonable to assume that a local team would at least pull similar numbers to the Raiders, and probably larger numbers given the AFL's stronger attendance culture.
Social media analytics are split depending on the platform. Google Trends is probably most accessible and easy to use for example; interest over time goes the AFL's way (2016 and 2019 onward are the only years the NRL wins), but the breakdown of interest goes the NRL's way by 8% or 54% to 46%.
Basically what data we have is admittedly shaky, but that it is what it is. In so far as it's useful it shows that neither sport is significantly more popular than the other.