To be clear on the level of absurdity this reaches:
Assuming average crew loss rates (i.e., not instapopped) and a busy day, I calculated at one point that I could be killing between 400,000 and 500,000 ship crew a day. One person, doing not-very-hardcore PvE. Having talked to some nullsec people, I suspect someone doing "hardcore" ratting could kill up to 800-900 thousand a day.
Now let's assume for a moment that there are 1,000 people doing PvE in EVE at any given time, a very conservative estimate. Now we're at 400-500 million people per day.
According to one source I found, Earth's population currently grows at a rate of around 230,000 people a day; thus, it would take around 1,740 Earth-like worlds to support the impact of capsuleers doing PvE. This might not seem like such a big deal - there are around 1,900 empire systems - but for the fact that it is a best-case estimation which uses a (in my opinion) exceedingly low number of crew killed by PvEers, completely ignores crew killed in capsuleer-vs-capsuleer actions, and also does not take into account those killed in structures we explode nor crew killed in other "semi-PvE" activities like FW and exploration.
A more accurate number, in my opinion, would be something close to 700-900 million on a given day, requiring between 3,040 and 3900 Earthlike worlds to support.
Just from what capsuleers do. Not including anything that happens around us.