The website, in my opinion, is not yet optimized in mobile use so I think it will be laggy when to use it in a mobile phone. I think an application would be great but most of the time the developer is not going to develop one since it is going to cost big amount of money. So maybe big casino websites only or real casino company is the only that is going to attempt to try this.
Based on my experience almost all gambling casinos related to crypto are optimized for mobile because I can play without any lag maybe it will lag if your internet is not stable but for me, I don't experience lag yet in mobile.
Most of the websites right now are optimized for mobile except for old websites.
However, for the apps, they mostly not developing it because of the budget but there are some ways to convert websites into apps but it's not actually needed for new casino games if the website is already optimized for mobile.