You’re not wrong, but lots of breeds are bred for just such a purpose, particularly thoroughbreds. They’re very expensive animals. Losing those competitions would come with consequences.
Consequences? Other than financial cost what are you predicting?
Horse meat would be a few euros cheaper.
Those horse might have been medicated at some point which basically means that you need to either cremate them or get a digger...
I think a case could be made that if there is a "valuable use" for elite horses that stimulates breeding more of them, horse meat would decline in price from the availability of surplus horses (similar to there being plenty of greyhounds to adopt).