Game runs on Unity Engine which is not very good by itself, but on top of that, Blizzard clearly can't handle it very well, even after all of those years of using it. Better technology could help improve overall experience (less laggs, frame drops and bugs). so I see potential for a sequel.
The sequel should just replace what we have now with everything transferred over. It needs to be rebuilt from scratch and made much more efficient (so that my laptop doesn't sound like a jet engine) - also things randomly just get 'stuck' all the time. I don't think we would necessarily need to see the difference, I would gladly take the same game with optimised code. Perhaps the current version is what is limiting it in terms of animation speeds and other QOL improvements they could be making but can't. Unity engine is ancient! It will need an upgrade at some point.
The only thing I would have liked them to add were counter cards that you can play on your opponent's turn. Right now I feel HS has way too little interactivity between players' moves. Just start with something little and maybe expensive so it's not straight ahead bonkers. See if players like it.
For instance, a 8 mana spell that lets you polymorph any minion played. So basically it prevents many OTK scenarios but makes you skip 1 turn. OP? Against combo decks definitely. Against aggro? Most likely a dead card.
I hear this question pretty often actually. The funny thing is that they started to generate it after the Overwatch 2 reveal.
But here is the thing that you should understand - Hearthstone is a whole different story compared to Overwatch. It's not something that requires the sequel simply because it can always be easily updated by the new cards, mechanics, modes, anything else. Overwatch 2 is more like work on mistakes - we launched, we saw the potential, we learned our problems and we are making something completely different but with the main idea kept in its core.