What are you talking about? The “AAA” classification has always been a measure of corporate involvement and budget, not of quality. If you think that being large in scale and having good production quality is what makes “AAA” games, you’re dead wrong.
When people say Valve doesn’t have a monopoly, they usually mean they don’t engage in anti-competitive practices (like making exclusivity a condition for publishing on their store, cough cough).
Actually, Valve’s recent moves represent what free market capitalism should be about - when competing stores started to appear, they instead made massive contributions to Linux gaming and appealed to right-to-repair advocates with the Steam Deck. Now both of those demographics are suckling on Gaben’s teats, myself included.