"Give me your phone, give me your laptop" works pretty well.
My phone has a giant "setup parental controls" button. You can block specific websites using tools like PiHole that are easy to set up.
One parent said their daughter was “completely addicted” to social media
Have you tried parenting her?
I love to shit on companies for doing evil shit (like Apple removing Targeted Display Mode from their iMacs), but Apple did the right thing here, but communicated it in the worst way possible.
I had an old iPhone that would randomly shut down when it drew too much power for the old battery to provide. If they hadn't done the fix, I would have had to get a new phone; it just wasn't reliable anymore. With the fix, things were slow, but they worked. Honestly, this is the opposite of planned obsolescence.