>>713106161 (OP)4 stars usually see better life when they are supports of some kind, when they are supposed to be an on-field damage dealer they have their work cut out for them but with the right combos they can end up pretty competitive but rarely as good as a 5 star.
i heard Ga ming is pretty good these days due to the plunge artifacts and supports.
Yanfei has a pretty solid kit in my opinion but Pyro is a pretty narrow element to work with, you pretty much just do Vapes or Melts, i would use her over Klee at least.
it is fun building a character wrong on purpose, i got a Nilou Bloom team and run Barbara on triple elemental mastery and use her as the on-field bloom trigger, shit is hilarious her weakened healing just barely allows her to survive blowing herself up.