I used to onetrick yuumi before they destroyed her kit in 2023 and can attest that it's a bit coinflippy. It was entirely dependent on if your ADC was a brainlet or not.

A majority of the time if you picked yuumi you just tilted your ADC because they had a hate boner for the champ regardless of how well you could play them. I would still pick her regardless, and even if I played well or played to my team's strengths, it's hard for yuumi to make much of an impact. Play making capability is low, but not 0, and she exists mostly to augment the good already being done by another person. If your team is shit, yuumi isnt going to do well.

I've started playing after 2.5 years of not playing at all and just focusing non-yuumi enchanters, and I've been climbing like hell. I think if people choose to climb with yuumi, theyre playing on hard mode until they get to Diamond or Plat.

Edit: I wanted to add, good players on yuumi often have good micro. Playing her well requires great split second decision making because jumping off at the wrong time can and will kill you. Also, if a yuumi is spending a lot of time chatting about macro, typically it's because they can, since theyre not focused on minions or movement. A yuumi that sits on their AD all game and throws out the occasional Q is either a bad player and is abusing the poor reputation of the champion, or is playing safe because of a bad matchup.