One of the main reasons Thor's attacks are so effective is that somehow he can bypass Loki's magic and even block his healing factor. It's potent enough that he can be decapitated and simply put his head back on but according to Thor (And Loki agreed.) if he decapitated Loki, he can prevent Loki from returning. Or another time when Thor crushed Loki's arm and forced him to heal normally and not through magical means.
I can believe this. But all beings who can heal or have healing factors can be koed. Ko is all it takes for a win here. Also I'm not sure the writer was thinking about Thor bypassing Loki's whatever when he had Thor hit him. It seemed that the writer just wanted to show Loki being rocked by pure physical power.
The explanation I gave was an example of a reason as to why Thor can do such damage against Loki.
Thor's always seemed to be more effective against Loki than others. He just straight up manhandles him at times while on the other hand Loki treats Beta Ray Bill, Masterson Thor, and Dargo Ktor as children as he slaps them around and one shots some of them. He casually erases Bor and brings him back a being clearly beyond Top Tier. On another occasion Loki can harm Surtur with the Twilight Sword, create illusions that can deceive him with his power and hold his own in a fight or go toe to toe against the Multiverse rocking, Galaxy busting Seth in his own realm. In other instances Loki is portrayed as practically a damn reality manipulator bringing shit to life, erasing beings, and basically doing whatever he wants.
Loki is pretty damn ridiculous in terms of power and magical ability.
And against Thor it's not just talk about power. There is one particular incident where Loki DEFINITELY could've defeated him with his power, but just haaaaad to duke it out physically.
Not that severe. Thor has been portrayed as simply above Loki. The ability to bypass his defenses simply shows a reason as to why his so damn effective at times. There's also the reason that Thor is magically resistant, and he can just literally smack away magical spells as if they were physical objects.