Hearthstone and MTGA are both digital card games, but they exist on different planes. Both can exist in this universe though, as they are differently designed card games and both have their strengths and weaknesses.
Many people complain about the hearthstone meta and it could get boring. But it would be disingenuous and wrong to say that this same thing does not happen with MTGA. Are there more combinations and potential for deck diversity in MTGA, yes, buy you are still going to get rolled by the top 4-5 decks that are on top of the meta. I swear when people complain about aggro in hearthstone and then talk about how MTGA is so different, they really never got higher than bronze rank. Mono red in MTGA can steam roll anything if it has a great opening hand, and you can be dead by turn 4. MTGA also has many counter and destroy spells which could become tiresome after awhile. Especially when you have Teferi decks that just counter and destroy your board and their only win condition will take 35 minutes. This control teferi deck is a top tier deck BTW.
I just want to say what i like about both of them.
Hearthstone
-Fast games
-Enjoy the RNG in moderation
-Interactions and overall play just feels so tight.
-Deck themes that start to emerge. I still have fun playing bomb warrior.
-Can be played on multiple devices.
-No counters so you don’t have to worry about everything being nullified straight from you hand.
-They made it so it’s very rare that aggro can roll you before the game even gets going.
-You don’t have to worry about mana
MTGA
-Longer games and potential for best of 3. This allows counters to the deck you are playing and adds more tactical depth.
-More tactical depth.
-Deck diversity is bigger
-Potential to counter your opponents plays so they can’t pull some frustrating shenanigans on you.
-Very low potential for nonsense RNG card generation. You usually* have to play whats in your deck.
So the 21st century gentleman/woman can have both of these games in their life. As they hit different notes for different folks. One can exist if the other one does also. You can enjoy both without wanting the other one to die or being in some sort of ultimate competition. I promise.