However, I really believe blockchain still has very big role to play in gambling industry. We are going to see new blockchain based superior gambling dApps in coming years which will disrupt crypto gambling completely by removing trust factor.
It won't really disrupt centralized gambling until full scalability is achieved. You can place hundreds of bets per second (and some people use it with official bots), without paying any fees in centralized gambling. And thanks to the provably fair system, exit scam is the only risk, which is pretty rare in crypto gambling.
Currently yes but I doubt the potential of blockchain will be limited to PoW. I am very positive that soon a newer algorithm will come into picture which could be used to secure blockchain as well as solve problem of scalability.
We already have algorithms like DPOS which are being used by networks like EOS and claim to process millions of transactions per second with no fees. Although, DPOS showed some signs of centralized system, it has open doors for others to come up with a similar system but comparatively more decentralised.