To elemental phial Charge Blade users: Artillery, Sharpness, Attack, Affinity... none of these skills affect your phial damage. Only specific element up does.

Does artillery affect elemental phials?

so, element phials get no effect from artillery skill. ... normally your element damage will cap at a certain amount but the phials can benefit from the skill being maxed out.

Does artillery affect power element phials Iceborne?

Artillery only affects the impact phials.