> It is still a "collectible" card game, from a very reputable company, with a lot of expected longevity
That's 3 elements you mention. Lets see:
> It is still a "collectible" card game
Yeah, it is, but only the last X expansions are valid for play. So old cards become invalid for standard play. (Forgive me if I used the wrong term for 'standard'; I'm an old Magic: The Gathering player who has seen Wizards of the Coast adopt this model in the 90s; Blizzard just copied it.)
Hence,
> with a lot of expected longevity
is rather relative.
> from a very reputable company
Activision Blizzard, Inc. or Blizzard.
As for reputable, well. Blizzard is very good with RNG in their games. A lot of their games are evolving around RNG, and loot, trying to keep the player playing for their dopamine shot. Lets see: Warcraft 3 was already about RNG (it contained loot), then we got Hearthstone (yup), we got Diablo 3 (yup), we got Overwatch (yup), we got Starcraft II (nope, standard RTS, doesn't contain crit AFAIK), Heroes of the Storm (not sure, not into MOBA at all, seems not?).
Blizzard are the masters of RNG. Not every of their game is P2W (Pay 2 Win), I admit that, but if there is one of these where RNG or loot matters and be downright bought, it is Hearthstone (you can buy gold in WoW legally, but not loot). If you want to play a game competitively, forget Hearthstone. The only fair game mode is the single player one, and the arena one (which requires in-game currency).
They're also masters of grinds, that's deeply entwined in every Blizzard game except Starcraft II. Fat grinds with shortcuts is one profit model. Not all Blizzard games have this model, but one of their games stands out: the P2W Hearthstone game.
> There are so many Gacha style games that are WAY more of a rip off than that.
I don't know that game. I'm sure there are evil schemes out there, but I know about this particular company and this game and this game type quite well.
If you want to play Hearthstone competitive you're going to have to shell out like 200-400 EUR per expansion. Some successful players and streamers can afford, but it stays a gentlemen's elite club that way. Just like Magic was a game for rich student kids. Been there, done it.
And let us not forget, we are ignoring that we're getting children, teenagers, and young adults hooked on gambling.