People like to do this a lot. "Game A looks better than Game B, but Game A runs better"
Graphic quality does not necessarily equal the game's performance. There are many other factors that culminate to how a game will perform, such as the engine, the skill of the developers, and individual hardware.
Minecraft clearly wasn't built in mind with these shaders, therefore you can't just slap these kind of visual effects on a game like Minecraft and expect it to run like Half Life 2 (which is nearly 12 years old and used a lot of baked lighting rather than dynamic lighting). Half Life 2 is just a poor example in general. That game handles lighting and shadows completely different than SEUS does.
I'm guilty of asking for some kind of miracle answer on how to get these shaders to run better as well, and what we need to realize is that there's already a lot of technical work being done underneath that makes these shaders run better than they really have any reason to for a project being worked on by a couple people at most for no direct monetary gain.