Its actually less true if you go for strength because strength increases your damage with strength weapons 5% and increases your physical armor by 2% so it provides a different bonus. But the bonus you get from dual wield and finesse are the exact same, which means there is no reason to put points into dual wield.
On top of that there are a lot more different types of finesse weapons than there are str weapons which means leveling polymorph in order to get finesse gives you a more diverse range of usefull weapons than if you leveled it for strength.
Strength weapons are one handed weapons and two handed weapons.
Finesse has ranged weapons, one handed weapons, daggers, and Two handed weapons (spears)
Leveling any of the weapons types (two-handed, dual wield, ranged, etc) gives you 5% more damage with that weapon type as well as some other bonus (1% crit per point in ranged, increased crit damage for two handed, and 1% dodge for dual wield) So because finesse and dual wield give the exact same bonuses it really only works as a true replacement for leveling dual wield.
However for example if I where to put 2 points into ranged, that would be 10% more damage with ranged weapons. If I where instead to put 2 points into polymorph and level my Finesse that would still be 10% more damage with ranged weapons, and also every single other type of weapon that uses finesse.
Polymorph has ruined the need to place points into leveling your weapon types for finesse weapons especially.
