It's definitely a problem, and not just for new authors. One of my oldest friends has over 30 books out (disclosure: a few of which I've proofed and/or edited) and has gone from niche publishers (TSR/WOTC) to self-pub and now trying small press again. They're currently very much surviving on Patreon support and an occasional RPG book sale.
(Sidenote: Loving 'Cruel Provocations'! Will say more later - only six chapters in but it's got its hooks - or possibly threads - in me. 😉)