Man,you’re saying that STR becomes weak, but in reality it’s rather the other way around and INT gets considerably weak. High level monsters have low DEF and high MDEF, giving most monsters a way higher resistance to magic.
The thing the developers should do is to actually give the mobs a really high block rate that favors investing points into STR rather than making STR even stronger, because, let’s face it, STR already gives 4 substats (weight limit, attack, critical attack and block penetration) while DEX only gives 3 and INT is still only adding 1 stat (magic attack).
If I had to chose which stat to balance, I’d rather look at INT and SPR first (and maybe at CON too) before doing sth to STR or DEX that could break the game easily…