I do not really get why the economy of this game is called greedy, I have literally played dozens of online CCGs and MTGA is the most consistently generous one if you know what you are doing.
I think it's 'cause there's no easy/decent way to exchange cash for wildcards. Going from 0 to top tier deck that runs 40 rares and 10 mythics and 10 uncommons is an absolute motherfucker, particularly in historic. Playing standard and gradually getting pieces for historic stuff you're interested in isn't shabby at all though. It's also nearly impossible to reach a complete MTGA collection which isn't unreasonable given they're rolling out older sets into historic, but the fact remains. There's also the fact that the "Vault" mechanic is pretty user unfriendly and you can't do anything with your 50 alternate printings of shock from 15 different sets even though you have a full playset of each.
Actually out of curiosity I'm gonna roughly compare how many commons it takes to get enough dust for a legendary in Hearthstone VS opening the vault and getting a mythic wildcard in MTGA. 1,600 dust to craft a legendary, you earn 5 dust per common to scrap, 320 common cards for a legendary in Hearthstone. MTGA vault takes 1,000 points to open and each common is worth 1 point, so 1,000 commons for a mythic (And two rares and 3 uncommons). Hearthstone packs are also 5 cards (1 guaranteed rare (Essentially uncommon in MTGA) or better, rest random) while MTGA non-draft packs are 5 common, 2 uncommon, 1 rare or better. So ignoring that Hearthstone packs have more swinging value (Most common and shittiest being 1 rare 4 common, but you could get multiple legendaries, multiple epics, etc) the typical Hearthstone pack would move the needle around 8 commons (Rares dust for 20, and since I'm comparing tearing packs down into the rarest card type let's say you're only pulling the worst Hearthstone packs and you have all the rares) while the typical MTGA pack would move the needle 11 commons (Uncommons being worth 3 vault points, also ignoring MTGA packs that give common and uncommon wildcards). In both games you earn roughly a pack a day (Technically you can get two packs a day from Hearthstone, but you have to poopsock daily wins for it so I'm disregarding it) so it would take about 40 days/packs of breaking down Hearthstone packs to craft the rarest card of your choice, while in MTGA it would take 91 days/packs to open a vault. And remember the Hearthstone rate is at the absolute worst, if you have freakishly and ungodly bad luck and you crack 40 packs without pulling anything better than the bare minimum and never once opening any foils. Also worth remembering that a Hearthstone legendary is more "Impactful" than a MTGA mythic, since most (All?) Hearthstone legendaries are singletons for a deck, while a mythic can go up to 4 in a deck.
Not trying to bitch too hard since I'm largely in the "MTGA's alright" camp too, but they still could unfuck the economy more.