why is csgo so hard to play ?

Although watching people on YouTube is not a bad idea, I feel the best bet you can take is to just take your time and learn the game and find your strengths and try not to expose your weakness too much. Take it slow and have patience and you'll find that will make you better than average on CSGO. Not your typical run and gun, definitely take a more cautious and alertive approach each game. Also find a weapon you feel very comfortable with and master that bad boy.