Other sports cost to entry to participate is $100-$500. Racing cost to entry to participate for one horse is more like $30-$50k
The only reason for that is their capacity to earn money if successful, which again is down to gambling. Otherwise they’d be giving them away for free at the gates of the glue factory (OK exaggeration but intrinsically true)
Racing owns that much land they would just need to shut clubs and go smaller if gambling was phased out
99% of people who attend the races wouldn’t go if they couldn’t bet, and anyway the industry is supported mostly by the people who don’t even attend
Goes double for greyhounds