How should we deal with the spread of reprehensible acts that people consider normal, such as shaving the beard and letting one's garment hang below the ankles (isbal)? And is it obligatory to denounce everyone who commits these acts in public places?

The spread of abominations, resulting from weak faith and ignorance, is addressed through educational da'wah activities in mosques and schools, and individual advice for those who are likely to benefit and whose evil is not feared. It is not necessary to pursue everyone. Advice to Muslims involves guiding them to what benefits their religion and their worldly life, teaching them what they do not know, enjoining good and forbidding evil gently, and showing compassion towards them. This is obligatory to the extent of one's ability, as long as the advisor does not fear harm upon themselves.