In brief: YouTube has become the service where teens watch the most videos, replacing Netflix in the number one spot for the first time ever. Both platforms remain hugely popular among younger viewers, but time spent on YouTube has been rising lately as time spent on Netflix slightly declines. Investment bank Piper Sandler's 46th semi-annual Generation Z survey of 9,193 US teens (via CNBC) shows that participants spend 29.1% of their daily video consumption time on YouTube. Netflix was a close second at 28.7%. The Google-owned service took its first-ever lead thanks to a small rise since the Spring and…