Just use Altcoins that has cheap fee and fast transaction confirmation like Tron, BSC and many more instead of using LN since you will still need to convert your Bitcoin to LN in able to deposit on it. Besides LN is still not popular among gamblers as an alternative to cut transaction fee compared on using altcoins.
Why not accept both the Lightning Network and altcoins? The more choices for deposit methods, the better for the casino.
¯\_(ツ)_/¯
Plus it was a mere suggestion. If the casino evaluates that it will be more work but with less benefit, then that's OK.
With the fact that LN users is still low, casino do not need to evaluate anything about the possibility adding LN.
If it gives many benefits to the casino, there must be many casinos that integrate LN already.
I cant even mention 1 casino name that use LN, maybe there are some but as far as I know, most popular bitcoin casinos in the industry has not added LN yet.
Suggestion is always appreciated ofc.