Hmm, if had helpers, would need to "share".
Last someone checked, was on the range of 8-10k/month, even assuming it is declared for tax reason and that Patreon gets a good percentage of it (I don't know what is the percentage Patreon takes exactly), it still makes for the equivalent of a nice salary (especially if it is not declared, honestly, I am quite confident in many countries Patreon would pass unseen).
So, no helpers, plus, the fact there are less alternatives, means people cannot go to someone else, in itself a further guarantee for DL.