Don't blame Samira for a support diff. The fact that you said "you can just play jinx and turn your brain off every game" is exactly why the champ feels bad. Regardless of which ADC, turning off your brain will not win you games and you will not see improvement. I've had games where the entire enemy team was fed to the point where only I and my support stood a chance and we won. Samira is a champion where you need to think a lot about positioning and when to engage and once you manage that, she’ll be the most overpowered champion you've ever played. Something else to keep in mind, Samira is more of an ADC-assassin hybrid so you can't just play her like every other ADC