Casinos are built with marble and expensive and fancy artwork because the owners understand math and psychology and thus how to best separate people from cash (and profitable guests from unprofitable ones). I know people who've been told "I'm sorry, sir, but we can't accept your play here, you're too good" (read: they would legitimately win at blackjack counting), they're quite happy to host profitable losers. Gambler's ruin is definitely a thing (I've seen it happen with advantage players), and the casino has far more money than most players do.

I'd say in over 50+ stays in Vegas over decades (including hotels like Bellagio, Cosmo, W=A, Wynn, Venetian, Palazzo, Delano, Four Seasons- some of those multiple stays at said properties) I haven't experienced really any outrageous service failures, but I'm pretty self-service when it comes to my needs, and I am definitely not inhabiting the high roller bracket (I've been adjacent to it through friends and acquaintances as you've been though). It's definitely not white-glove and personalized treatment of the five star hotel type until you get into the very highest echelons of play though. Thus my calling those Vegas hotels (save for maybe the 4S) "five stars" with full on air quotes treatment. It's really not unless you're truly going to shell out lavishly.