That type of advice depends on particular circumstances so you have to explain the different situations so kids are not confused by getting mixed messages.

(1) sometimes the effort is more important than the result. E.g. kids attempt to cook a meal for Mother's Day and they burn the food a bit. Or one is self-learning dancing or pottery and the results are not professional quality and it doesn't matter.

(2) but sometimes, the result is more important than the effort. The "real world" out there such as job performance reviews, college entrance SAT scores, etc cares about the results. If the judge finds the results unacceptable and the only comeback is "but I tried really really hard", it will be perceived as just making excuses.

Each situation above has also been misapplied. The infamous "Tiger Mom" focused too much on (2) and criticized her daughter for a amateur hand-drawn Mother's Day card and told her to do it again. Likewise, employees are sometimes blindsided and shocked for being fired for "underperformance" because they misapply (1) to the employer/employee relationship.