Block the shit already then. Block it at the router, get rid of that fruit phone and get something you can have more control over - i.e. a rooted AOSP-derived Android distribution with a few extra tools installed - if you child absolutely
has to have a 'smart' phone. If not and he - or most likely she given the TT addiction - absolutely needs a phone there are plenty of 'dumb' phones available to fit those needs. Yes yes yes, I know all about the supposed ostracisation caused by teens not having a phone but if the alternative is to give up your child to the CCP and the tech moguls I'd choose the former and send her/him to a different school.
Here's what I´d do if a 'smart' phone is a requirement:
- ditch the fruit phone, get a device which is supported by LineageOS.
- root it. Install Timelimit [1]. Install the required server somewhere under your control. Make sure Timelimit is configured as 'device administrator' so it can not be removed or circumvented. Install it on your phone as well and maybe on your wife's - if she can be trusted not to give in too easily when your child wants to have more time than you allotted. If she is a pushover in this respect you'll have to take the lead and suffer the consequences of having your child and your wife see you as the big bad wolf but so be it.
- No google account on that phone, no play store. Install F-Droid and Aurora Store. Install AFWall (firewall) and configure it to only allow those apps which really need to have network access. Put a password on AFWall so the firewall can only be edited by those who know it - and make sure your daughter/son does not get to know it.
- She/he can now only run those apps which you allow him or her to run. You can remotely add and remove apps which can be run, add or remove time for those apps/categories/... (the thing can be configured just how you want it, from a single 'phone can be used for X minutes' to a hierarchy of categories each with their own rules on when, how long and how long in a single stretch after which follows a forced break apps in those categories can be used.
- Timelimit is not a remote control tool, you can not see what your child is doing with the device. I don't like spying on my children so I intentionally do not run such tools but they do exist. I'd advice against using them unless you suspect foul play (grooming etc) because I consider these to be a breach of trust.
The combination of Timelimit and the firewall give good control over which apps can be used and when/in what way they are used. As long as there is a browser on the device it can be used to reach undesired services like Tiktok so that is something to keep in mind: limit generic browser access.
Best would be to simply not give the child a 'smart' phone. Second best is something like this, a device which you can configure to reduce the incentives for those 'hours of mindless scrolling' - don't allow such apps and put forced breaks on browsers, e.g. 5 minutes of access, 15 minutes forced break. If the child needs to have longer access for some reason let her explain why and grant it piecemeal.
This is what I do for my 14yo daughter who also 'had to have a phone' according to my wife. There are no social media apps on the thing, she has access to our own XMPP server through Conversations, she can make photos, play music, do some browsing (with forced breaks) and has a total of 30 minutes of screen time per day for non-essential purposes. She has more time for reading books or playing music and actual phone time is unlimited as is the time for e.g. the public transport app which she needs to get to school.
Root out the plague of Tiktok et al, root and branch. You're the parent, you have the power to act, use it. On my network it is blocked at both the DNS as well as the IP layer - first using ipsets with iptables, now using nftables sets.
Devices can help but only if the parents are willing to use their parental authority - a dirty word according to many 'enlightened experts' whose 'expertise' is partly responsible for the mess we're in now - so use it. Ditch the fruit phone because it does not allow you the control you need. Don´t use a stock Android because it does not allow it either. Don't put a Google account on the phone, it is not necessary.
Will your daughter like it? No, not initially, not if she was used to having unlimited access. She might try to find ways to get around the limits so you'll have to check your network for unknown devices since she might borrow a friend's old phone to get her fix. If you find her doing this you of course take away that phone but you should not get angry with her. Limit her phone time for a bit so she knows she did wrong but keep it at that. Encourage her to do things with all the time she now has since she is no longer doom-scrolling, find other things to do - hobbies etc, these used to be common but seem to be rare nowadays. Eventually she'll get used to not being controlled by her phone and she'll probably end up liking the freedom this gives but to get there you'll have to bite through that sour apple.
I managed to keep my children (14 and 20) away from 'social' networks so I probably had and have an easier task than what awaits you but I think the effort it worth it. No good comes from having your children mind-controlled by the nefarious actors behind 'social' media. I hope you give them the good example by not using these 'services' either?
[1] https://f-droid.org/en/packages/io.timelimit.android.aosp.di...