The new pick order swap.
The fact teams can now freely shuffle pick order at any time and don’t trade champions ever means one-tricking is more viable than ever if someone is really that confident in their matchups. There are people that can potentially play their one champion 99% of the time unless the other team incidentally has FP and got it. I’ve seen this with Katarina players that have literally nothing else in their match history.
How to tell OP has never played toplane in their life: