Life is hard. Life can be draining. Life can just seem too much sometimes. Most of us find ways to deal with these feelings if they arise or block them out completely, some of us just don't manage it.
When it's someone who seemingly has everything it's easy to look for specific reasoning or mental illness, but ultimately, all of us need a point to live or reasons to fight past sadness or bad shit happening never mind depression, even more so in first world problem terms, when you don't have much to do to survive day to day and personal issues and feelings can build up and seem so much more intense.
The saddest thing about suicide, even more than the useless waste of a young life, is the pain loved ones have to endure. It's a deep scar that never, ever leaves, and deaths like this reverberate through those closest's entire lives.