It's because you're used to western RPGs where levels are 1 to 100 or 999.
Just divide by 100
Let's use a different example:
"It's over '9000' !!!"
Or "Friezas base power is 530,000".
Perfectly fine. Because there is some basis to compare it to. It has meaning.
Or you could look at Doroki (briefly) in One Piece.
Or the countless series I read with levels varying across the board.
My issue has to do with numbers go brrrrrr,
and having nothing meaningful to compare numbers(I'll take one or the other, not both). No basis towards whether levels are additive or more multiplicative. No basis towards where anything stands compared to each other. No standard towards what might be considered the highest level, or "level cap"(point leveling further is not realistically possible)
Is a level 6400 human beating a level 7000 boss wolf and a bunch of lv 4000 impressive at all? Or is it routine with humans higher intelligence and weaponry(and abilities).
Meanwhile the artwork doesn't have anything in particular to scale combat and how powerful the combatants by either.
The fight is identical with level 1000/4000/7000 wolves vs 6000 human, as it would be lv 1/4/7 vs lv 6 within the same story.
I would wager this is probably an issue with the adaptation, and the LN probably has something to compare or relate to.(as adaptations commonly water down and skip information contained in character thoughts)