Are anti-fog coatings actually effective, or marketing fluff?

Reviewers are split. Foam-gasketed or goggle-style designs (like the Dewalt DPG82 Concealer and Klein 60471) hold up best when paired with respirators or in humid environments, according to r/Tools and r/engineering threads. Open-frame anti-fog glasses work well at first but multiple verified-purchase reviewers note the coating degrades over months of cleaning.