The first champion i bought and mained was Akali who i thought was pretty easy to play kit wise. However, when i first started playing her was right after her biggest nerf, when her E stopped proccing her Q, when she went from pick or ban to a little over 40% winrate.
I quickly learned that Akali's kit was easy, but she was really weak at the time and the majority of lanes countered her without adding pink wards (which revealed her) to the mix. What playing such a difficult champion to survive with in lane forced me to play smart and think about what i was going to do before doing it. Playing Akali taught me how to play the game smart, how can i win this fight without dying? If i do die, is it worth it? Learning Akali when she was at her weakest point really helped me learn game knowledge.
Even now Akali isn't in the best state, but she's much better than what she was. Her biggest counters, the 75g pink ward, and lee sin E, when he could just stand in the middle of Akali's shroud, press E and revveal her, have been removed which makes her feel a lot less constricted when playing her than what it used to be.
Like you, i have a love for a champion with a kit that's considered pretty easy. From what I've seen champions with harder kits are generally given more tools they can use to outplay an enemy champion. If, for example, a fiora or riven lose to Akali, it's not necessarily because of Akali's braindead kit, they just didn't use their champion to the full potential and got outplayed. Of course there are exceptions, the last thing i want is for people to think that if they play a mechanically difficult champion they can get out of any situation and can always outplay the enemy, that isnt true. Sometimes it has to do with luck, positioning, cooldowns, practice, experience, etc.