MF is cancer for the ADC meta
I'm not saying she's OP, or she's bad; I'm saying she's a terrible champ design wise for ADC. Her laning is good with Q and E harass, and then her ult is great in teamfights with the Black Cleaver-Youmuu build; she doesn't take any "AD carry" mechanics to perform decently. You can stick a midlaner or a toplaner who can CS well and knows not to run straight into the enemy and they can succeed on MF; again, I'm not saying she's OP or good, I just think design-wise she's a terrible champion. If she pops off she'll nuke your team with an R, which isn't characteristic of an ADC, and if she does bad she'll get one shot by a burst champion; she just seems like a terrible champ design-wise.
than against
or
anyday.
or
, who have clear weaknesses unlike jacks-of-all-trades like
or
who can do everything and do it quite well.
are the same tier, the difference is MF trades their mobility and ranged poke for huge AoEs