My children are very tech aware and they love tech!
My children are now in yr 8 and yr 6 but have had phones from year 4. They've had PC's from at least then too if not before.
I don't think phones or computers are inherently bad. It's just important they are used mindfully and parents ensure good monitoring and education around their use.
My children benefit from the independence their phones give them. They have benefitted hugely from using their pcs for gaming, building things, developing and creating games, writing, making animations, youtubing, etc.. Computers are incredible technology and my children have gained so much. My youngest also enjoys learning to make the world of the PC come to life through 3D printing etc.. very creative.
Phones are so useful where we live. My children coordinate meet ups with their friends, chat to each other and take their phones when they go out and about so I know they are safe and could be tracked if needs be.
Both my children are very sporty, creative, intelligent and well rounded individuals, like many other children their age. I would say that the tech has done them no harm and in fact, has aided their skills and creativity.
It isn't the phones or the pcs or the tech that is bad. It's just important to use them correctly and with adult support for children and young people.