I feel like SC strikes a happy medium between accessibility and technicality, it's barrier for entry is reasonable enough that the majority of ppl can pick it up and play it in no time, yet there's definitely enough high level mechanics and techniques in there for the more hardcore players
all that said, i still prefer DOA, but i do feel like SC is designed better overall
For me SC is rather a gem. It is extremely fun due to it being the only fighting game to use swords and weaponry to attack the opponent with, but the combat at times can be a bit slow. DOA became my favourite 3D fighting game ever since I've played DOA2, but I like Tekken too because it was my first fighting game that I've ever played and thoroughly enjoyed.
Yeah, SoulCalibur is an incredibly underrated game in the FGC and implied by Camel, arguably has the best balance between casual accessibility and appeal, and hardcore technicality. I think due to how different it feels to most FG's (i.e. Not 2D, not heavy on the combo emphasis), it may initially turn off the FG players that are used to how other FG's generally play.
Dead or Alive's another FG that is very underrated in the FGC. Similar to SC, DOA has a good balance between casual, pick-up-&-play gameplay and hardcore depth to the mechanics for those that dig deeper. But similar to SC, DOA's mechanics can initially turn off people from playing the game due to it playing differently to how FG players are used to (in this case the Hold system for example).
all that said, i still prefer DOA, but i do feel like SC is designed better overall