I agree OP 8 is too young to give a child a smart phone.
There are so many dangers of what and who they will be exposed to but also damaging is what they will not be doing, playing, art and craft, being active, face to face friendships.
I wish that the age limit for social media was 16 or even 18 and properly policed.
Roblox is awful in my opinion, not safe at all. I don’t trust any multi player online game for children. I came to the conclusion that quality paid for games are the safest choice. However as with phones generally, particular games and social media there is a lot of pestering and apparently all other parents are very lax, of course the children would say that wouldn’t they.
The current generation are guinea pigs with this technology, it wouldn’t surprise me if they have a lot more rules and protections in place for their own children.
Adults find it hard not to use phones compulsively switching from one app to another and are susceptible to the manipulation of apps and advertising, children are even more at the mercy of these controlling forces and at a time in their lives when we can only guess at the impact on their development.
My main tactic was just saying no to a phone until secondary school (11 years old) and sticking to the age guidelines for apps and games. Even at 13 no Instagram for girls because it is particularly dangerous for eating disorders, self harm etc and very manipulative, no tiktok due to the lax child protection. Parental controls enabled until the end of secondary school (16 years old) to facilitate sleep and homework.
The school recommended everyone in the family putting phones downstairs somewhere over night and I wish I had done this from the start because I never managed it later and relied on parental controls on the phones instead. My DC insisted that they needed phone alarms, audio books, a meditation app, music etc at bedtime. I started up the habit of leaving my own phone downstairs and find it helpful so every so often I suggest it but they remain unconvinced.