I did read and also noticed someone else understood your comment similarly and also felt like pointing it out. Surprise, perhaps people that aren't in your head might interpret things differently and there's at least two people here that did.
I could see people getting addicted to luxury and developping unhealthy spending habits. In fact, I'm pretty sure that's fairly common. Someone else mentionned clothes and fashion before in this thread, to parallel your luxury restaurant argument. If they feel compelled to spend for luxury for a reason or another, it is a problem, it is an addiction, and gacha games can make you feel that. It has mechanisms that make it so that you must keep spending to retain status.
Heroes's business model has you spend to remain relevant. There's a power creep, that you've also constantly denied or sought to minimize through your posts and with each shiny new things, each new more powerful things, the game makes it's players feel like they need to keep on spending to remain on top. Or at least to stand a better chance to. That's also an aspect of it that I consider unethical.
Then there's the loot boxes gambling aspect of it that you've mentionned yourself.
You say the amount doesn't matter but I believe the massive amount of money that's invested in such a video game by some of it's players amounts to addiction one way or another. Whether it is getting the whole collection of collectable units, or getting extra merges for the team, it can amount to several thousands, which is just several orders of magnitude higher than what most video games sell for or expect you to spend on them. It's insane. Promotions aside, the best orb for buck deal right now is 143 orbs for 105 bucks, which is essentially on average probably 2 or 3 5* units, half of them only being the focus unit you desired. Gunning for several +10 merge projects is a huge investment for anyone, including those with deeper pockets. It is such irrational spending when compared to what's asked of you by the rest of the vgame industry that it can only be done through addiction and the entire model depends of finding ways to get it's players addicted before hitting you with things like barriers to progress, particularly in PvP, where you compete against opponents in higher tiers that are mostly all big spenders.
Even PvE content can hardly be beat my f2p players. You argued before that it can be and pointed towards guides online, but these are produced by exceptional players that have invested several hours into finding solutions. For the greater majority, some of the game modes will be unbeatable unless they replicate the strategy, which is not really playing the game at all, or do what the game wants you to do: pay to win.
How much have you spent? Getting close to 100k? Despite the limits you've imposed on yourself, despite the budget you have for it, despite that you're an adult and despite who the fuck am I to tell you how to spend your money and what makes you happy, that's irrational spending and that's gotta be rooted in addiction.