Why is he wearing a mask? Anyway, 3M company got good exposure to promote their brand for free.
Isaac Haxton has been wearing a mask through and after Covid 19.
Naturally, I can't speak for Haxton personally but the answer for millions around the world would be as Covid 19 is still rumbling across the globe and still taking casualties, so many still wear masks.
US deaths now stand at 1.166,663, and yesterday Covid 19 tracking reports hundreds were diagnosed with Covid 19 in
france but actually several thousand in South Korea for example. Around Asia though most countries are not mandating wearing masks governments are still recommending doing so when using public transport and meeting in numbers. The latest variants are not as lethal and treatments have improved but many want to avoid infection and the possibility of 'long Covid'.
Additionally for what it's worth, many also learnt a lesson regarding protection from regular pollution (most cities have a poor level of air quality due to traffic) and regular flu seasons. When people wore mask in the pandemic, the spread of flu was almost completely arrested.
So as large poker tournaments are notorious for spreading germs (before Covid 19 even appeared) I assume Haxton wears a mask because it makes sense.