[blub]

There’s different kinds of “masks” and different kinds of “work”

FFP3 are the standard for protecting against airborne disease and they work as intended. That’s literally one of the purposes they’re designed for. FF2/N95 also work quite well, which was known for a long time, including from SARS and MERS studies.

Work can mean that they prevent transmission or reduce the risk. It might have been worth wearing a surgical mask, as I remember reading that it did reduce risk enough for it to be recommended in Germany once the establishment got over their mask procurement predicament.

Finally, original Covid was not as contagious as current Covid, which is one of the if not the most contagious airborne disease.

Based on e.g. SARS it would have been rational to recommend FFP2 masks, as was done in e.g. South Korea. However, incompetent Westen governments utterly failed to make such masks available to the population, so they tended to err on the “no evidence masks work” side.