Look, let's be honest - what gives you or others the right to steal from others?
I think technically it's copying more than stealing
Like if you could wait for someone to design and build a car and then CTRL+C/V it for yourself (is it possible to steal in a post-scarcity society?)
In a reasonable world, we would be imposing high taxes on all LLMs and using that money to fund grants for future writers and artists. It would be good for the LLM makers in the long run, since it would give them more fuel for their models, and it would be good for the artists and writers because it would provide sustainable, reliable wages.
Unfortunately, that isn't the world we live in. LLM makers don't seem to care about the impact they will have on society or even their own livelihoods, as long as they get rich today. And in addition to all the regulatory capture, we are having our governments gutted on the mere fear that they might do their job and prevent the wholesale looting of society by these new robber-barons.
So with the economically-optimal approaches off the table, we have to fall back on imposing false scarcity in the hopes that maybe capitalism can limp along.
But you call it "stealing," others call it "copying."
Stealing takes, from someone, something they own.
As long as discussion of a work that has published is not impeded, the public is not harmed even by these 50-years after life copyrights other than by that they are accumulated by certain companies who themselves become problems.
When someone decides to use someone's work without compensation he is, even though he is not deprived of the work itself, still robbed. But it's not a theft of goods, it's theft of service. The copyright infringer isn't the guy who steals your phone, it's the guy who even you have done some work for but who refuses to pay.
With this view you can also believe, without hypocrisy, that what the LLM firms are doing is wrong while what Schwartz did was not, since the authors in question weren't deprived of any royalties or payments due to them due to due to the publishing model for scientific works.