There's no such thing as them being "good" or "bad". It all depends. It depends basically on what they're being used for, how the user uses them, etc. If someone is spending hours per day watching inane youtube videos of fluffy cats or playing mindless games like Candy Crush, then clearly that's not good.
But lots of games have very valuable educational value, such as Minecraft which is very creative and educational, especially when you come to create your own Worlds, create your own interactive games, etc. No one would whinge if your son spent a few hours playing with Lego, but Minecraft is basically the same virtually, in fact it's better as you have unlimited "bricks", world sizes, etc.
Even the likes of FIFA can be useful in terms of "managing" your money (coins), to earn them, strategically buy/sell players, etc. My son used to spent more time on playing the transfer market than actually playing football on it - identifying players who may increase in value over the year, etc.
As for googling, etc., he was always looking at different things, just out of curiosity/nosiness.
We've always been a bit worried about his screen time, but we've always made sure we know what he was doing on it, had comprehensive parental controls in place so he couldn't watch unsuitable content, buy things with real money, etc. and insist on him playing/watching in a room with us instead of being in his bedroom alone.
We needn't have worried. He's just about to graduate with a first degree in Mathematics, and is a mature and well rounded adult now, already secured a good job in a blue chip firm that he starts in the Summer. All his online activity/gaming has given him a massive amount of knowledge and he is his Uni college quiz team captain in inter-college quizzes.
By the way, he's not read a book since primary school, yet still got grade 9's in his GCSE English Language and Literature, as well as grade 9s in History and Geography - all "traditional" subjects where you'd think reading books was essential - he got those grades by watching online videos!