If you steal my book from the "Emergency Library" instead of buying an electronic copy, I get financially impacted.
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.
>> "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.