Right, the purpose is to actually arrange for legitimate competition. Ideally, we would split by whatever facets actually make sense; consider something like fighting disciplines where the split is by weight, or auto racing where it's by the class of vehicle, power-to-weight ratio, etc.

The problem is that there is only so much attention to go around, so we cannot have too many splits; depending on the sport it might just not be financially doable. We also don't want the split to be effectively "the best" and "the second best", because nobody is going to fund millions in advertising for the second best. So, a split like men/women is not surprising as a historical compromise to ensure there's still some attention on those competing in a lighter weight class.

Generically changing it to lightweights/heavyweights might be a reasonable compromise as well, or an age line, or something like that; it will depend on the sport and the market to draw that out. I wouldn't at all be surprised if the thing that makes sense is to continue with the existing split, though....