The antonyms for "letting slide" are "holding accountable," "demanding responsibility," "being strict," "perfectionism," "rigor," "vigilance," "discipline," and "scrutiny." When we let things slide, we ignore them or don't take action, and this can cause problems in the long run. Holding oneself or others accountable for their actions can lead to better outcomes, as people take responsibility for their mistakes and strive to improve. Being strict and maintaining high standards can ensure that work is done to the best of one's ability. Vigilance and discipline are vital in ensuring that rules and regulations are followed, leading to a more efficient and effective workplace.