Lies, damn lies and statistics.
Disagree with you there chief. The sport is constantly changing. Numbers go up and down. It's easy to look at a few races that get canned and say the sport is dying. The small races are often run at a loss and they do it tough. Sufferfest have just dropped the Rottnest races which is a shame. Awesome place to race, just very poorly attended. But then they have a sprint on in Perth the following week and it's full. You could argue that IMWA numbers are low, 1200 in 2018, but then there's now a 70.3 same day, so you have 2000 people racing. Buss 70.3 in May has been hit hard, really bad luck, swim canned in 2017 for some waves, dec 2017 swim canned, may 2018 swim canned and this year weather was terrible.... putting off more people. Many had to be pulled out the water. They are now moving the race to March.
It's also a sport that has a high rate of attrition, I played rugby for 30 seasons straight, many of my mates did the same thing. 3 - 4 years seems to be the average time a triathlete spends in the sport. So numbers will always ebb and flow.Crossfit, F45, tough mudder took a few numbers, but they seem to be dead or dying now. Triathlon/Ironman will always be the holy grail when it comes to endurance sports.