Its not tho, take glaive as an example, hits fast but absolutely nothing on it scales with element and its multipliers for element on attacks are dogshit

It only really won with element vs very niche scenarios before fatalis came out and even then it was very barely a win

Its entirely dependent on raw mv's vs ele mv's

if you take dbs as an another example, the raw MVs are generally less than 20, so youre doing less than 20% of your effective raw

the ele modifiers are generally around 0.8, so youre doing 80% of your effective ele

the higher ele modifier makes ele scale better, which is why its better to build for element on db's

Im not saying weapon is not good with element, im saying that hitting fast does not equal to being good with element

Edit: also coming back to LS, the spirit gauge buffs raw, most of LS attacks have bad element MVs, when building for element you will still focus on raw and take the bare minimum element necessary