This sentence means that sometimes, in order to achieve positive results or outcomes, there may be negative or questionable consequences that are considered necessary. In other words, certain undesirable effects or trade-offs may be accepted or justified because the overall benefits outweigh the drawbacks.
This sentence suggests that there are certain negative or questionable outcomes that, when considered together with positive outcomes, are deemed necessary. In other words, there may be certain undesirable consequences that are accepted or justified because they lead to overall beneficial results. The phrase "on balance" implies that a careful evaluation of both positive and negative outcomes is being considered to determine if the overall outcome is favorable.
