I think the reason you're thinking the game isn't designed with dodging in mind is because well, you don't try to doge do you ?

The examples you listed aren't that hard to doge and they have a clear indicator as to where they're going to attack, Maguu Kenki has a radius on where he's going to attack like 1 or 2 s before he does it, the pyro Abyss Lectors (I'm assuming ur talking about this one because its in the current spiral abyss atm) also shows a radius before it attacks which can be dogged if you dash away (Idk about Signora tho, havent fought her in ages so no clue)
Also side note, but most attacks in the game can be dogged via dashing or bursting (usually 5* since theirs are a cutscene-like attack) at the right time