> pointing out that this will make it harder for them to eat and pay rent during the isolation period.

This implies that "during the isolation period" modifies "harder to eat and pay rent" in a meaningful fashion. Restaurant workers are having a harder time paying rent.

Authors save for a privileged minority have traditionally struggled to pay rent as well but presumably no more than normally.

Now I understand your point, which is a reasonable one. The situation is that the economy in general is tanking, people are not going to bookstores, etc., so authors, who, as you point out, are not wealthy, have even less income now. In other words, it's a particularly cruel time for the "Emergency Library" to be taking money out of their pockets.

So if most authors don't make a whole lot anyway if copyright went away or was drastically limited but you received basic income and medical would you be better off or worse?

You assume that everyone reading a copy of the book, would also be willing (or able) to purchase it. That’s not the case.

That’s too absolute: nobody is arguing that there’d be a 100% purchase rate but it seems highly unlikely that there will be no sales impact from having free copies available from a reputable source with very high search-engine ranking.

Such is the risk of absolutes...

>> "nobody is arguing that there’d be a 100% purchase rate"

The typical case against things like this does multiply downloads by sale price under the assumption each one is a lost sale. I've seen authors (obscure and prominent) scream about how many hundreds of thousands of dollars they're missing out on because they found their book on some torrent site.