I think its mostly due to the fact that most casinos accept other coins besides bitcoin and since someone can use another network like ETH which is fairly cheap now, there probably wont be much use for the bitcoin lightning network. I think that these days there are more people using L2 like Arbitrium or blockchains such as Solana which got ultra cheap fees that the lightning network doesn't have much demand, and since there isnt much demand there isnt much use for it.
The bitcoin mempool is getting less congested and it is now at 8 sat/vbyte which is just $0.69 for 1 input and 2 outputs. Bitcoin transaction since many days ago are getting cheaper.Look at many CEX, look how long it took them to implement Lightning network when it was in fact possible right after Segwit went live back in 2017.
Even most centralized exchanges are not supporting lightning network. 
