You can protect your kid for a while, but sooner or later your protection becomes a bigger problem.
And be prepared for everyone to call you a conspiracy nut. But you eventually let that roll off your back when you see how happy your kids are just being kids.
Most problems we face in our lives haven't changed a zilch - its simply interacting with people for whatever reasons. You don't need phone for that, in fact you should first work on handling face-to-face interactions and only then move to remote ones.
Kids can grok how phone and app works in few weeks through and through and much faster than you or me currently, so that they are not missing anything if they start later. There is very little to 'learn' by further usage of it, just feeding addictions.
Lets not act like parents are stellar in this, because more often than not they aren't and most issues with kids come from this direction (as a parent of small kids I really can't blame anybody else if we mess up something, not at this age)