Honestly,

They are meaningless terms because there is no real settling on what constitutes as casual, midcore, or hardcore.

Like, you have some people who think EX is casual, you have some people that think EX is midcore, you have some people that think Bozja and Eureka are midcore, just as you have some people that think savage is midcore, and some people that think it is hardcore, and just as you have some people that think Bozja and Eureka are casual.

There are some people who think it comes down to what content you consume, there are people that put it down to how much time you spend doing the content you consume, regardless of what that content is.

I would say don't get too caught up in very loose, or open-to-interpretation definitions.