DD is 17 now.
She got a phone with no sim, so basically an ipod, when in Y5. She could log into our wifi, similar to her tablet but only in shared areas, she didn't have it in her room. She listened to music, audiobooks, played games and took photos.
In Y6 she got a sim after Easter. She had a brick phone before as she walked alone and also was all day in the stable on weekends, so we could communicate. It worked ok but she wasn't happy not having a smart phone and it caused bullying in school.
In secondary a smart phone was basically normal. Some apps were used by the school, she needed the bus app, train app, maps. She got WhatsApp with 12 because texting and emails is not something they do at all.
She was 15 before Snapshot and 13 before Instagram. Insta also had controls that we had to agree to her posting a photo and we monitored who she followed and who followed her.
Her phone was monitored until she was nearly 16 and she couldn't download any app without our approval.
I agree that smartphones do cause problems but unfortunately the world developed around them and schools take advantage of technology as well, so you are an outsider socially and helpless when it comes to practial tasks without one.