Funny you should mention that, because esports is a big reason people don't strategize anymore. Back in League's earlier days, before esports were the focus, people used to try all kinds of crazy stuff. It was the golden era. A really fun time to be a League player.
Then Riot started touting so-called professionals and everyone started mirroring them. Now it feels like a lot of players can't adjust to a champion if a pro team hasn't done it (or had to do it). It's almost like people who can't navigate to the grocery store without the map function on their phone, you know? Reliance effect or what have you.
I think it's bad for the game. Because as you say, if people would just stop and think a little, just about anything can be overcome. (Except Garen. Beating a decent Garen is 80% luck no matter how sharp you are.)