This is one of things that I used to be able to do, that I miss the
most.
Yes, you could. I feel a big difference hugging a loved one goodbye when they enter the security maze, compared to when they disappear from sight at the gate. They dribble away at the security maze, but man, at the gate they're taken from you. You see the plane door close and suddenly they're not even breathing the same air as you.
And when the plane taxis away, if you're at the gate you can press your face against the glass and watch, and wave if you're lucky. At some airports, like Seattle, it's possible to watch the plane through the entire taxi and takeoff. When my (now ex) wife flew from Seattle to China, I remember watching the MD11 take off, and following the plane until I couldn't see it and then the exhaust until I couldn't see it and finally watching nothing but empty sky.
Security theater merely irritates and angers me, but here they've taken away an emotional thing from me.