My very first shiny was a female Combee. I had just beaten the first gym and noticed a swarm of Combee on the town outskirts. One of them was a very obvious darker yellow...
I have caught three more since then, each one Pokemon that are very obviously shiny in the overworld (pink Fenizen, pink Oinkologne, and pink underbelly Dunsparce, which was very apparent as it gets startled and starts to jump when you get near it). Once I've completed the game and gotten the tools to maximise shiny hunting (Charm and food), I would really love to hunt for a shiny 'Iron Valiant'.
I agree with the general sentiment that overworld shinies has made it easier than ever to get shinies, even in spite of my relatively short play time in the game so far. Personally I don't mind, some trainers get WAY too elitist about their shinies, and while it's cool that they're rarer, they should still be able to be enjoyed by more casual players as well.