Unless alipay and whatsoever pay comes with cash back or perks for the user, it won't gain a following in Malaysia. Why should I use those pay and earn nothing from them when I can use cc and get some of my money back?
Not if consumer are not adopting it. You can offer super cheap fees but if the customers are not using and they demand for Mastercard and visa, the merchant have to comply or they will lose their customer.

If you are talking about hawker, no hawker in their right mind will use these QR codes (every profit matters to small time hawker). Maybe in KV in the future but not in East coast or Sabah and sarawak. Cash is still the way to go. Don't believe me, go to your nearest wet market and pasar malam. See how many people using phone to pay. Transactions is still carried out via cash. Heck, maybank and Cimb (2 of Malaysia largest bank) also have wallets but you don't see it being adopted by the masses.
Unless they are willing to burn cash to give perks. Otherwise those who have been hacking cc (using the right card for the right occasion)  to get double digit cashback will never adopt it.  You need these users to adopt it.

That's just people who actually spend money on mobile games. Not your everyday uncles and aunties who go to wet market,  coffee shops and pasar malam.

In China, I can only imagine how do they manage the changes when thousands of people if not hundred buying stuff with them .. they might need to carry bags to the nearest banks

Bags as in notes received by the hawkers from their thousands of customer. Just look at the populations in China, theyight just don't have enough time to count and make changes.

That refers to your opinion in why China is a success but not here.