As many people suggest that parents should become friends once their kids enter teens. Do you think it is required?

Yes. But a special kind of friend who still have to set rules and be tough when need to. They sometimes need someone to set boundaries for them or use their parents as an excuse for not wanting to join in some activity. So it's a transition from authoritative to more friendly because at the end of the teens it's the adulthood and U definitely need to be friends with them. I won't say be friends overnight but gradually? See ur child's maturity and his appetite for more dangerous stuff. Set some ground rules too