Im playing the game for 10+ years at this point and I’ve definitely spent a lot of money on it, but I like playing League therefore I don’t think its wasted money if it makes the game actively a better experience for me. So my answer would be: 0$ wasted, at least a few hundred to 1000$ spent over way more than 5000 hours of playtime.
If anyone is toxic to you, just mute the chat and/or the pings (since a large amount of people don’t use their in any way that is constructive), there’s absolutely nothing wrong with that.
Sadly it is often the case that someone writes something mean or condescending and if you can’t deal with that, then just mute them.
I can especially advise to just disable the All-Chat in your settings, since it is officially THE MOST USELESS FEATURE in all of league of legends. The only thing that happens in all-chat, are taunts, trolls or flames. There is no constructive conversation happening in all-chat, so there is literally no point in keeping it activated during ranked games.