I am experimenting with using freedom.to to block social media in the browser. It creates a VPN profile that blocks these sites in the browser (it also uses the Screen Time API to block specific apps). The downsides are that you can just go into iOS settings to disable the profile, and I am paying Freedom a subscription for something I could set up for free. The upside vs. managing it myself is that it's much easier to create a schedule (eg block during weekdays, instead of block 24/7).