Loki was bullied in childhood, but there is no evidence in the comics or the films to suggest that the bullying was of a physical nature. In fact I’d argue Loki was more neglected than bullied, and starved for validation, not ridiculed (though certain lines on Volstagg’s behalf in the films suggest there may have been moments of the latter form of abuse).
It’s more a phenomenon in which Loki was “Othered” by his culture. He was, both filially and institutionally (because Odin, the head of his family, is also the head of State and cultural arbiter), pitted against a certain desired socio-cultural standard of forthrightness, aggression, and hypermasculinity, as the undesired alternative, in every day small interactions and in the society in which he was raised. At the very least he suffers from internalized racism for this very reason, living in an imperialist society that literally sees people of other realms as economically dependent subhuman colonialized species (particularly the Jotnar).
Frigga, another Other (because she was a woman and witch), recognized this and it’s because of Frigga that this misconception is as egregious as it is. Because Frigga clearly taught Loki not only how to use magic as an intellectually driven deceit in battle, she also taught him a very particular dance-like fighting style that involves rapid attacks, spins, and repeat attacks, such that the enemy can never get a good hold on you at close range, and it’s probably because of Frigga that Loki is so adept with a short blade:
Probably the most vivid demonstration of Frigga’s signature fighting style, which maximizes SPEED and AGILITY at the expense of upper body strength (in other words, ideally suited to Loki’s athletic but non-muscular body type) is when Loki disarms like four or more Dark Elves in Svartalfheim single-handedly without gaining a single scratch, in the span of seconds, just in time to rush to and rescue Thor from Kurse.
So while physical STRENGTH is not Loki’s forte, he has a great deal of physical AGILITY and ENDURANCE, and his ass was kicked in a more verbal and cultural way than a physical way.
Modern Life is Rubbish 