Hmm my understanding differs...I'm pretty sure that hypothetical 1000$ of profits from those t shirts is essentially a tax write off. Because let's say their profits are 10 000$ from everything-not-Covid merch. Those earnings gets taxed (let's say 10% so 1000$). Since they've donated through the Covid merch profits (which are completely fan-funded), they should get a tax break and not be taxed the whole 1000$. So yes, they benefit tax wise while making unnecessary t shirts during a pandemic.
It may differ in different places, but I think what you're suggesting is that you give to charity rather than paying tax. And I think it's much more common that you don't pay tax on money that you give to charity.
So to use your examples if you make $1,000 of profit on Covid merch and $10,000 on everything else you would owe $1,100 tax at a 10% tax rate. But if you tell HMRC or IRS or whoever you're dealing with that you gave a thousand dollars to chairty, then your profit is just $10,000 and you only have to pay $1,000 in tax. But if you'd though 'huh maybe the poeple invovled in making and distributing merch are people' and not made the shirts in the first place. Then you'd still have the $10,000 you'd made from everything else and you'd pay $1,000 tax on it.
There may be some advance accounting which allows you to write off some expenses that you wouldn't have been able to otherwise, and if anyone has any knowledge I'd love to hear from them.
But like I said before. It seems strange to me to go hunting around for other ways COVID-19 is bad. What we know is enough.
