Well. There's some feel-punchy stuff going on in the world of SuMo if you pay attention and explore some. Real-life stuff that might be familiar to some people.
On Melemele Island, there's a house in which some guy laments the fact that his kid basically took off without much of a word. He says "I was the one that got beat". The kid's room is covered in a fine layer of dust...and there's a golf bag in the corner that contains "a great number of broken and bent golf clubs".
Also on Melemele, you've got the graveyard. Graveyards and people mourning their pokemon in them are nothing new to the series, but on a revisit (I discovered that Misdreavus could be found there and I've never had one before, so I went a-running) I found an old woman being carried around by a Machamp. Turns out her husband is buried in that same graveyard. He died in a traffic accident and the Machamp (who spent most of the scene weeping) would have died as well had the husband not returned Machamp to its ball just before impact. The widow entreats you to be very careful while riding pokemon around so you don't suffer a similar fate.
I'm...not used to feeling depressed while playing Pokemon. I found both of these in quick succession.