For you
I drop my phone at least once a day lol
I actually dropped it more before I got a case on the Pixels because the back glass is ridiculously slippery and it'll even slide itself off surfaces that aren't perfectly level. Back glass needs to fucking die.
The insanely polished smooth metal frame doesn't help either when combined with the ultra smooth glass back in my hands.
I never go without a case now. The thicker and grippier the better. I also have a belief that phones these days are too thin, and I would gladly have a thicker phone with better battery life. The best feeling phone in my hand IMHO was my Palm Treo, which was almost an inch thick.