Riot seems to only know three kinds of nerfs...
The first one is the "nerf" that is so minor it's borderline nonexistent and treated as a joke, like taking 5 AD away from Vayne. The second one is the nerf that overshoots and cripples the champion, like what happened to Kog'Maw with the most recent patch (52.78-44.22%; worst ADC win rate, 5th worst overall). And the last one is when they successively nerf a champion, bit by bit, until they have nothing left, often not even their items.
This is why people fear for the livelihood of their mains whenever they start to get popular and/or strong. Sure, sometimes Riot will get it right and succeed at simply toning down a champion, like with the nerfs to Graves jungle or the recent nerf to Nautilus top, but it seems that more often than not they don't. And often when they dumpster a champion, that champion is left to flounder for ages before they get buffed back up to the point of relevance.
Meanwhile, other champions are left virtually untouched for ages while remaining consistently strong. And I'm not just talking about champions who become strong and are allowed to stay that way for longer than we'd all like. There are others, like Amumu, Janna, Malzahar, who never seem to drop out of that 52-53% win rate sweet spot. The only positive there is that's 3 favorites of mine I don't have to worry about getting gutted.
However, I can't say the same for a number of other favorites of mine. Tahm Kench, despite still being near the top of everyone's hate/ban list, has been at about 46% win rate (top and support) since the start of the season. Lulu isn't really relevant outside of solo lanes anymore, her support win rate also around that 46% mark. Plus, more nerfs appear to be coming, ones which'll only hurt her supporting even more. Ekko now only sees success in the jungle, which is one of the two roles I tend to avoid (it and ADC). Poppy and Nautilus will probably wind up down in the depths (pun intended) with them before long thanks to their LCS popularity. And, if that happens, that'd be my entire champion pool (minus Morgana), and all the champions I love the most, in the dumps.
So, Riot, can we please go a little easier with the nerfs in the future? You know, but not so easy that it becomes a meme like "-5 AD."