I have horses. Three horses. One a meat rescue baby. I have owned, loaned, been around, ridden and worked with horses for most of my life.
I really don't like racing (and I am not alone in doing so amongst the many equestrians I know -from my experience it is one area where 'the equestrian world, two people, three opinions' doesn't stand). Particularly dislike flat racing, where horses young enough that their skeleton isn't fully matured are pushed to the limit of their capabilities to make rich people richer and poor people poorer (while the lower leg growth plates are fused by 2 ish, hocks don't fuse til 4, humerus til about then too, spine til 6). Then there's the exercise induced pulmonary haemmorhage. (And ftr no any dead horses can't go into the human food chain, their passport will have had it stamped out, plus they're incredibly likely to have been given bute at some point which would preclude it even if their passport didn't). I have seen the damage suffered by many ex racers...spinal, leg and gastric issues. Many get put down once they've left racing into leisure homes as a result of these issues.
Advances made in motorsport filter down to day to day drivers - safety systems etc. All intensive breeding of thoroughbreds does is produce yet more generations of horse who might be startlingly fast but who you'd need a second mortgage to feed cos they can't keep weight on and a third one for the farrier because by and large they have terrible feet. You need shares in sudocrem for the mud fever they seem to be able to get even in the height of summer. And their grandsire is also likely to be their great grandsire.
However, there are many things I disagree with in the equestrian world. I disagree with jumping youngsters (immature hocks).
I don't like the 'kick and pull' style of riding many schools start kids off with. Don't like seeing increasingly harsh gadgetry on horses in place of adequate schooling. Don't agree with indiscriminate breeding, there are too many neglected horses as it is. I could go on but I won't.
However. Racing is never going to be banned. Kids are never going to stop having lessons. Etc.
All I, and anyone else can do is not support the things I don't agree with, not bet on races, go for private instruction over riding school and/or choose a riding school very carefully, and ensure I keep my own horses as absolutely humanely as I can and in as natural a way as possible. What other people do with theirs, if it is within animal welfare legislation, isn't for me to try to change, much as I might like to.