Jeezo. Secondary children have been wearing masks all day in Scotland since after the first lockdown and it is both fine and enforced - although it apparently doesn't need much enforcing at my DS's school as the young people there care about each other's health and welfare.
Language teachers stand 2m back and unmask when necessary for pronunciation. PE is unmasked but outside. masks are only removed for eating and being outside. My son's large secondary only had one case between Aug and Dec.
Despite being massively keen on washable masks for environmental reasons, DS prefers a disposable mask for school which is fine, it is a long time to be wearing one.