I think it's intentional as they said explaining in the developer's q&a (they intentionally didnt include sucrose's em sharing to kazuha elemental dmg bonus count) and the update notice (they'll be changing the way the description is written i think?? because they said kazuha is working as intended)

but on my own opinion im starting to realize how different kazuha is from sucrose. He's more mobile and easy to use than sucrose (sucrose is squishy for me and yes i dont have zhongli) and I can CC more often with kazu than sucrose. But of course that doesn't erase the fact that sucrose is op characters in so many aspects lol.

I think a year or 2 down the line, we'll see more characters having talents/skills/kits overlapping. I think mihoyo has to be more creative in their next characters or else we'll be seeing a lot of comparisons later on.