I shall wear a mask if requested, either verbally or by signage, in the same way that, if requested, I would take my shoes off when entering someone's property - their property, their rules. And, if it makes people around me feel more comfortable, albeit maybe a placebo effect, then so be it.
However, why anyone thinks these flimsy bits of material (especially when half of those that do wear them seem to think, for reasons best known to themselves, that their noses have nothing to do with their breathing in and breathing out) actually do any good is beyond me. For the first two or three months of the pandemic, we were assured by both the WHO and the government that they were ineffective. In fact we were told that they did more harm than good due to the constant touching of our faces when putting them on, taking them off and adjusting them. Plus the contamination of the mask itself.
And, of course, people legitimately remove their masks when eating, whether in a hospitality environment or on public transport. But as far as I know there has been no research to show that the passing on of infections is miraculously halted for the duration of all meals.
There was an experiment last year, run by scientists in Denmark, in which 3,000 volunteers wore masks and a further 3,000 did not. 1.8% of those wearing masks caught Covid compared to 2.1 per cent of those who didn't. The scientists concluded that the difference between the two groups was 'not statistically significant'. https://www.spectator.co.uk/article/do-masks-stop-the-spread-of-covid-19-
With regard to travel by public transport, the British Rail Safety and Standards Board concluded, after experiments, that the risk of infection per passenger journey was only 1 in 11,000. https://www.rssb.co.uk/en/what-we-do/insights-and-news/news/Rail-still-safer-than-road-during-Covid-19