I disagree. Going back to RLWC2013 from round 2 to the quarter finals England played three tier two nations in a row and got three capacity crowds.
Was that because the standard was higher than a SL game? The scorelines and the respective squads of the opposition would suggest not.
Hand on heart did you expect those kind of crowds pre tournament?
People wanted to see England and the organisers made it in to a must see event for spectators, something the Kangaroos and RLWC17 team have failed miserably at.
What I mean is the RLWC as a whole, not certain individual games against tier two nations, is a step up. England/GB haven't won the tournament or beaten Aus in a series in 45 years, it's become the holy grail. Aussies are going for their 10th RLWC in 12. Lack of competition for the winners reduces the significance of the tournament, the lack of wins increases it for loser. Aus and NZ aren't like anything seen in Super League, plus most of the best English players play in the NRL so there is an added pull to watch England. Aussies are watching the cream in the NRL, and the international team lords it over the tournament. It's a complete contrast between the two nations. The elevated status given to the tournament as a whole in England means games against tier two nations did well in terms of sales.
Also factor in the short distances fans had to travel for games in England. Most of the games were in the heartlands, RL territory that also has a much denser population than Australia. Geographically all 11 English clubs in Super League span just 110 miles. Plus tickets weren't as expensive as Australia.
Games outside the heartlands, two involved Australia in Ireland and Wales which had 5k at both games. Bristol had 7k. In terms of interest in the heartlands and for England internationals the tournament was a success, outside that though it was disappointing. This tournament with PNG and Tonga has added more depth of interest than the last one.
https://en.wikipedia.org/wiki/2013_Rugby_League_World_Cup#Attendances