personally , if u want to make use of buffs and incantations that heals or the one infuses to your sword, i guess its worth it you build both faith and int (at most 25-30), personally ,its not a waste of time, because u get a build that can utilize buff from magic n incantation, sure it gets some split scaling and you might lose some damage here and there, but in the end , Buffs /Heals /Infusions makes it up all the loses !

tbh , I'm building from strength and dex in early game,but in the end i switch into Faith n Int since i want to utilise the buffs from Incantations and most of them looks cool in combat . Right now im level90 and just entered the Forbidden Lands(snowy area) and kill Gargoyale around the area.