One of my only problems with this premise is the fact that the book says "all the free stuff" is what's caused the collapse of the United States. Ignoring the economic questions of this, I'm pretty sure that most countries get away with socialized medicine and don't collapse. Here, it's clear that there's no "free stuff" for Mary regarding her cancer treatment and the plot can't advance without her financial ruin so I'm going to say this is the book's only plot hole.
Anyway, Mary finds herself digitally uploaded to a virtual reality world where she has to advance through the ranks of a punishing series of war games against countless scenarios. If she dies during the battle, she's deleted from the program. This is not Lit-RPG though and it is a staggering story of psychological damage and conditioning as Mary (now Brin) has her memories erased of her past life while being turned into a murderous killing machine.
Her teammates include the psychopath Syd, the old woman now young Suri, and a deeply troubled man named Walt. Everything other than orders is gradually erased from their mind with a large focus given on the fact that they are to be rendered sexless. Removing the libido from a computer program is probably very easy but leaves lasting psychological scars as one of the primary drives of human relationships vanishes from people who were not Ace in the first place.
Much of the book is Brin's struggle to reach Ten Sigma and "graduate" from the hideous program that seems like a combination of the SPARTAN II program from HALO and John Scalzi's OLD MAN'S WAR. It is an objectively evil thing but the author treats their horrific abuse dispassionately, which makes it even more effective. I got some serious SQUID GAMES vibes from the book and if you like the horrifying contests from that series then you'll almost certainly enjoy this book.
Speaking of which, this is a book that will certainly not be for everyone. In addition to the relentless punishing violence our heroine is forced to endure, there's also a lot of terrifying scenes dealing with sex, torture, and threat of rape. Syd is a horrific monster and the only one who can experience any form of sexual gratification, which he associates with killing as well. Charming guy. Needless to say, he tries to get our heroine into his clutches several times. If that causes you to nope the frick out then I don't blame you.
A.W Wang does an excellent job of making you sympathize with Mary/Brin through her horrific ordeal. They have a grasp on how to make the most mundane and normal memories seem like treasures beyond price as they're gradually slipping away in the deadening monotany of their training. If I have any complaints, it's the fact that the program isn't treated with quite the level of abject horror that it should be from most people but they've been brainwashed to serve it so it's understandable.
This is not the kind of novel you want to read if you don't want to get in the absolute grimmest areas of the human psyche even with a sympathetic protagonist but it is definitely well-written as well as exciting for those who like their science fiction dark as midnight.