It makes sense if it is like that, when they want to launch their own application they certainly have to spend money, and even if you look at the benefits which are indeed large they are certainly able to fund it, maybe there is another reason why they do not release their own application.
With me who occasionally gambles at local online casinos they always offer their application on the grounds that gambling is more comfortable, but I myself am more comfortable using it in web form.
I dont think that casino apps, that majority of casino have today, cost a lot of money. Have you ever tried downloading and running at least 5 or 10 of them? Either I am so lucky to get "such" casino apps, but they all look like an icon on mobile page that still open browser (kind of a bookmark) or shortcut icon on desktop to a page. I can say that they are real apps, as most of them can not be found on Apple Store or in Google Play. Bookmark icon that isnt store in browser - that is what casino app look to me.