I know every new car comes with issues but wtf

I got the 26 rav4 and one of the main things I found that I just can’t explain is that a couple of weeks ago when I tried to turn the car on it wouldn’t turn on. Ended up being dead battery. I’ve had this car for like 3 months it shouldn’t have a dead battery. And to get to the battery is an insane task when the battery is dead so the trunk won’t open. Has this happened to anyone else? Only thing I did that morning was wash the car and park it right back in the garage. I didn’t have it on while I was washing it, I don’t think I got water in any part of the car that wouldn’t tolerate water and the car was fine when I turned it on to park it back in the garage. Now I’m worried that it will do this some other time when I’m not expecting it and in some random parking lot.